buffer
Pluralbuffers
Verbbuffers, buffering, buffered
Pluralbuffers
Formsbuffers, buffering, buffered
- 1
- 2A spring-loaded device fitted to the ends of railway vehicles to cushion the impact when they make contact.
The buffer compressed sharply as the locomotive backed onto the train.
Worn buffers can transmit too much shock through the couplings.
Note
Railway engineering builds a vocabulary around it: buffing loads are the compressive forces taken when vehicles push together, which can be shared by the side buffers and the center coupler. Side buffers come in pairs at each end, which is why C. S. Lewis pictures goods trains crashing into "a thousand pairs of buffers." Keep it distinct from the barrier at the track's end, which stops a whole train rather than cushioning one car against another.
- 3A section of memory set aside to hold data temporarily, often before it is sent to or just after it is received from an external device.
The program copies each file into a buffer before writing it to disk.
Network buffers fill quickly when traffic spikes.
Note
A programmer's sense, concrete and countable: a region of memory with a set job. One process fills it and another drains it, so neither has to wait on the other's pace. The usual idiom is spatial. Data is read into a buffer and written out of it, and the act of holding it there is the computing verb.
- 4In computing, to hold data temporarily in memory until it can be processed.
Editing software buffers incoming footage so the timeline stays responsive.
Cheap players buffer constantly whenever bandwidth drops.
Similarcache
Note
The computing verb works both with and without an object. Used transitively, software buffers data or footage. Used intransitively, the player or stream itself is said to buffer, as in the video is buffering, meaning it has paused while data catches up. Both uses describe the same act, seen from the data's side or from the program's.
- 5A routine or storage medium that compensates for differences in the rate of data flow or the timing of events when transferring data between devices.
A small hardware buffer absorbs the timing mismatch between the sensor and the controller.
Communication buffers smooth out bursts so the receiver is never overwhelmed.
Note
In telecommunications the emphasis falls on timing rather than storage itself. The buffer sits between a sender and a receiver that run at different speeds, or whose events arrive at different moments, and it evens out the difference. It can be a routine as well as a storage medium. That separates it from the block of memory that programmers set aside.
- 6A neutral zone or state, such as a demilitarized strip, that separates two opposing powers and lessens the risk of direct conflict.
The region was kept as a buffer between the two empires for decades.
Diplomats proposed a demilitarized buffer along the contested border.
Similarbarrier
Note
Politics uses the bare noun as shorthand for two compounds, buffer zone and buffer state. A buffer zone is a strip of ground, often demilitarized. A buffer state is a whole country whose position between rivals keeps them apart. Context usually settles which is meant. Where it might not, the full compound is the clearer choice.
- 7A solution that stabilizes the pH of a liquid, resisting changes in acidity when an acid or alkali is added.
Chemists prepared a phosphate buffer to hold the reaction at a constant pH.
Several buffers are used in biology to mimic the conditions inside living cells.
Note
Chemistry's buffer is typically a weak acid paired with its conjugate base, holding the pH near a value set by that acid. It absorbs small additions of strong acid or base, not unlimited ones. The noun is often named for its ingredients, as in a phosphate buffer. The matching verb names the act of keeping a solution steady this way.
- 8A reserve of funds set aside to be drawn on only when adverse conditions arise.
The bank holds a capital buffer to absorb losses during a downturn.
Households with a savings buffer recover faster from financial shocks.
Note
Finance borrows the image of a cushion against shock. The word usually travels with a qualifier that says whose money it is. A household keeps a savings buffer, often reckoned in months of living expenses, while a bank holds a capital buffer. Unlike ordinary savings, it is meant to be touched only when circumstances turn bad.
- 9A person or thing that buffs something, polishing it and making it shiny.
The factory hired two more buffers to finish the brass fittings before the order shipped.
He switched on the buffer and worked the wax into the hood in slow circles.
Similarpolisher
Note
Here the word is simply buff plus -er, and it names people and machines alike: a worker finishing brass fittings, or the electric tool that works wax into a car's paint. The floor-cleaning machine and the shoe polisher are narrower kinds of it. The buffer that stands between two things is a different word, from an obsolete verb buff, "make a dull sound when struck."
- 10A machine fitted with rotary brushes that is moved across a hard floor to clean and polish it.
The cleaning crew brought out a buffer to restore the shine on the marble.
Industrial buffers can strip and polish a large floor in a single pass.
Similarpolisher
Note
Two unrelated words share this spelling. The floor machine is simply buff plus -er, something that buffs a surface to a shine. The buffer that cushions a blow comes from an obsolete verb buff, "to make a dull sound when struck," from Old French buffe, "a blow." That second word is the one behind the railway buffer and its many technical relatives.
- 11A machine designed to polish shoes and boots to a shine.
The shoeshine stand had an electric buffer for finishing each pair.
Old hotels often kept a buffer in the lobby for guests' boots.
Similarpolisher
- 12A barrier installed at the end of a railway track to absorb the impact of a train that fails to stop in time.
The locomotive came to rest just short of the buffer.
Damaged buffers at the terminus were replaced after the collision.
Note
The barrier at the end of the line gave English an idiom: to hit the buffers is to come to an abrupt, unplanned stop. Christian Wolmar, writing in 2024, recalls once questioning the value of Crossrail and suggesting it was "doomed to hit the buffers." The phrase is plural and takes the. It is used of plans and projects far more readily than of actual trains.
- 13Something used to maintain slack between objects or to keep separate objects apart.
Engineers fitted a buffer between the motor and its mount to keep vibration from spreading.
The buffer kept the heavy panels from pressing directly against each other.
Note
A mechanic's umbrella term, broader than any single part. A spacer, a pad or a spring can serve, as long as it keeps slack between objects or stops them bearing directly on one another. The railway buffer is the best-known particular case. The general idea, a thing that keeps one object from acting on another, is the one the political, financial and computing senses borrow.
- 14To keep the acidity of a solution close to a chosen value by adding an acid or a base.
Lab technicians buffer the reaction mixture to hold the pH steady.
Blood proteins buffer the bloodstream against small shifts in acidity.
Similarstabilize
Note
The laboratory verb, describing what a chemist does with the chemistry noun. The object is the solution or mixture, and the past participle often serves as an adjective: a buffered solution holds its pH. Mind the logic. Acid or base is added to keep the acidity from moving away from the chosen value, not to push it somewhere new.
- 15To isolate one thing from another, or to reduce the effect that one has on the other.
A strong support network helps buffer people from the stress of major life changes.
Wetlands buffer coastal towns against storm surges.
Similarshield, protect, cushion, insulate
Oppositeexpose
Note
The general verb, commonly followed by from or against: support buffers people from stress, and wetlands buffer towns against surges. Railway writing keeps a literal use. G. Freeman Allen in 1962 describes yard equipment designed to "buffer up the sorted wagons in the sidings" at no more than 4.7 m.p.h. That is the job the buffers on the wagons exist for.
- 16A good-natured, slow-witted man, usually elderly.
Some cheerful old buffer at the club kept buying everyone drinks.
She married a harmless old buffer twice her age.
Note
Usually paired with old, and meant fondly rather than harshly. Speakers even use it of themselves, as in C. S. Lewis's The Magician's Nephew (1955): "an old buffer like me." Dickens, in Our Mutual Friend, capitalizes it for a set of dull guests, the "stuffed Buffers" placed "between the rest of the company and possible accidents." The joke plays on the cushioning sense.
- 17A boxer; one who fights with the fists, especially for prizes.
The tavern emptied when the local buffer challenged a stranger to a bout.
Such a buffer as Donnelly, / Ereland never again will see.
1821, Pierce Egan (the Elder), BoxianaNote
Sporting slang from the prize ring, now archaic and tied to Ireland. Pierce Egan's Boxiana (1821) praises a fighter with the lines "Such a buffer as Donnelly, / Ereland never again will see." Today it belongs in historical writing or period dialogue. A modern reader who meets it without warning is more likely to picture a polishing machine or a genial old man.
- 18A dog.
The farmer's buffer chased rabbits across the field all afternoon.
He whistled, and the shaggy buffer came bounding back.
Note
British slang for a dog, now dated, and said to look back to buff leather. The Sawdust Ring (1934) uses it of a grieving animal that "ran disconsolately round the circus." Because it sits beside the "old fellow" meaning, a sentence using it needs something only a dog has, such as a tail, a lead or a bark. Otherwise readers may picture an elderly man.
- 19Comparative form of buff: more buff.
The actor grew noticeably buffer for the superhero role.
He's buffer than his older brother now.
Note
The comparative of the adjective buff, spelled exactly like the noun but working quite differently in a sentence. It carries buff's own senses: "muscular" in colloquial use, and "attractive" in Multicultural London English slang. So he's buffer than his brother is a remark about physique. The frame shows which word you have: after is, got or grew, or before than, it is the adjective.
- 20A circuit that isolates a signal source from its load to reduce the load's effect on the source, often taking the form of an amplifier.
- 21To queue up an input so that it is carried out as soon as the game allows it.
- 22The chief boatswain's mate aboard a ship.
Showing meanings only.
Practice
Can you tell the meanings of buffer apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.
Origins
This word is formed from "buff" combined with the suffix "-er".
This is an agent noun from the obsolete verb "buff" (to make a dull sound when struck), first recorded in the mid-16th century and taken from Old French "buffe" ("blow"). The "boatswain's mate" sense is popularly explained by the mate being a "buffer" or intermediary between officers and men, though various other explanations have also been proposed.
In reference to buff leather.