drift

Engineers pair it with jitter: the journal Broadcast Management/Engineering (1975) praises a servo system for "assuring minimum jitter and drift." Jitter is quick, irregular wobble. Drift is slow and steady, a creep that puts sound and picture out of step only over time. Here the noun is uncountable, so a recording has drift, not a drift.

Geologists use the word for what the ice sheets left behind, usually in the phrase glacial drift, as in E. Andrews's 1867 "Observations on the Glacial Drift beneath the bed of Lake Michigan." It is loose material lying over bedrock: clay, sand, gravel and boulders. It covers both till dropped directly by the ice and outwash sorted by meltwater, and where it buries old valleys, streams cut new ones.

Direction rather than distance: the word answers "which way?", so it pairs naturally with compass points. Richard Hakluyt's Principal Navigations (1589) says simply "Our drift was south." Carried into talk and argument, the same idea of a heading gives drift as the gist. To follow someone's drift is to follow where their words are going.

The current becomes the subject and the floating thing the object, as in the tide drifted the wreckage ashore. In the passive, a person can be carried along by circumstance. John Henry Newman writes in his Apologia Pro Vita Sua (1865–1866), "I was drifted back first to the ante-Nicene history," as though his studies had moved him without his steering.

The wind is the subject here and snow or sand the object: a current of wind drifts snow. Its intransitive partner, snow drifting into heaps, makes the snow the subject instead. The choice tells the reader whether attention is on the wind doing the work or on the heaps forming.

Here the word measures how far a current goes in a stated time, and says nothing about which way. Direction is the set, which is why drift as a course or setting sits so close to it. Keep it apart from a vessel's drift off course. Here the current itself is measured. There the measure is the ship's displacement.

Spin bowlers speak of drift when the ball moves sideways in the air, before it ever reaches the pitch. Turn is what happens after it lands. Swerve is the near synonym. Good drift changes the ball's angle of approach, so the turn off the pitch is harder for the batsman to read.

A screen problem more than a stage one, because a step off the mark can carry an actor out of focus, light or frame. Michael Pate's The Film Actor (1970) notes "another form of drift when playing in a scene with other actors." Continuity also suffers, since drift between takes keeps shots from cutting together.

Gunners' drift belongs to elongated, spinning shells, and a round ball does not show it. The spin that keeps a shell nose-first also swings it steadily to one side, the side of the rifling's twist. The error therefore grows with range in a predictable way, which is why it can be set out in tables and corrected for.

Mining uses this word twice over, which makes this sense easy to misread. A drift can be the tunnel itself, and that tunnel can also stray off line, so one sentence may speak of the drift of a drift. Context settles it: a drift that is driven or cut is a passage, while a drift that is surveyed, corrected or excessive is the error. The same idea of gradual straying lies behind a ship carried off course.

A metalworker's tool named for how it is used: it is driven through the metal, not turned. Forced through a punched or drilled hole, the tapered steel opens the hole wider or trues it, and broach is its near synonym. To use one is to drift a hole. Do not confuse it with the straight pin drift.

One of the oldest uses of the word, since Middle English drift already meant a drove. Animals make a drift because they are being driven, the same driving that piles up a heap of snow. Thomas Fuller's History of the University of Cambridge (1655) complains of cattle crossing a bridge "with their great drifts doing much damage to the high ways".

Miners drive a drift rather than dig it, and the word keeps that verb inside it through the shared root meaning "to drive." This one connects shaft to shaft as a small underground gallery. Driftway is the same thing under a longer name. The passage runs level or nearly so, which sets it apart from the shafts it joins.

Unlike the passage between shafts, this drift is blind. It is pushed ahead into the ground to find ore or to work it, often following a vein, and most end at a dead face instead of breaking through to another opening. Adit and tunnel are its near synonyms.

Here the tool moves the pin, not the hole. Set against a metal or hardwood pin and struck, it either seats the pin or drives it out, and the pin then lines up or locks the two pieces together. The tool is straight rather than tapered, because its job is to carry the blow cleanly, not to shape the metal.

The verb belonging to the tapered tool, with the hole as its object. The drift pushes metal aside rather than cutting it away. Plates are often drifted so that their rivet or bolt holes line up before fastening, which is why the verb so often keeps company with rivets.

American mining usage turns the noun into work: to drift is to drive an exploratory tunnel along a vein or ledge, testing it for ore as you go. The verb usually takes along (drift along the ledge). It names the alternative to sinking a shaft, following a deposit sideways instead of down.

Builders mean the sideways push that an arch or vault puts on the walls carrying it. Weight presses down, but drift presses out, and buttresses, tie members or sheer mass must resist it if the structure is to stand. When a vault's drift is underestimated, the walls lean before anything cracks overhead.