mm
- 1Symbol for millimeter.
Use a 6 mm drill bit for the wall anchors.
The lens has a focal length of 50 mm and a wide aperture.
UsageNo plural s: 4 mm (not
incorrect: 4 mms). Leave a space after the number and keep it lowercase. - 2Another spelling of mmm: a sound showing pleasure, especially at food, or used while thinking, hesitating, or agreeing.
Mm, that's a fair point, but the numbers still don't add up.
Mm, these strawberries taste like summer.
UsageWhen it introduces a sentence, follow it with a comma: Mm, let me think.
Note
The two-letter spelling does the work of mmm: relish for food, a pause to think, and in British speech a closed-mouth yes.
- 3Short for million: used mainly in business and finance, especially after amounts of money.
The fund closed with $250 MM in commitments, well above its target.
Analysts expect the deal to add $40 MM to annual revenue.
UsageWritten after the amount: $5 MM. Outside finance, spelling out million is clearest.
Note
Doubling is the point: finance often writes a single M for a thousand, and MM multiplies it to a thousand thousands, so $5 MM is five million dollars. In Roman numerals, by contrast, MM simply adds up to two thousand.
Checked 2 Nov 2026 · 3 facts
- In this convention, M represents a thousand and MM represents a thousand times a thousand, or one million. eia.gov
- $5 MM represents five million dollars. en.wikipedia.org
- The Roman numeral MM equals two thousand. en.wikipedia.org
Less common meanings
- 4Short for month: the two digits that stand for the month in a written date format such as dd/mm/yyyy.
European forms usually ask for dates as dd/mm/yyyy, while American forms put mm first.
The expiration date on the card is printed as mm/yy, so 08/27 means August 2027.
Note
A placeholder rather than a word: it reserves two digits for the month, so March goes in as 03, not 3. Its real work is to show the order a form expects, since 04/05 is the fifth of April where mm comes first and the fourth of May where dd does.
Checked 31 Oct 2026 · 2 facts
- In the specified date format, mm reserves two digits for the month, making March 03. docushare3.dcc.edu
- The placeholders specify month/day order: 04/05 means April 5 in mm/dd and May 4 in dd/mm. support.microsoft.com
- 5The number two thousand (2000) written in Roman numerals.
The cornerstone of the library is carved with the year MM.
The film's closing credits give its copyright year as MM.
- 6Short for mile marker: a highway sign showing the distance in miles from a fixed starting point.
Dispatchers sent troopers to a crash reported at MM 87 on the northbound side.
The exit numbers on this highway match the nearest MM, so exit 32 sits near MM 32.
- 7Short for market maker: a firm or trader that stands ready to buy and sell a security at quoted prices, keeping trading flowing.
When volatility spiked, the MM widened its spread to limit its risk.
The MM on the options desk quoted a bid of 1.20 and an ask of 1.25.
Note
A market maker's living comes from the spread, the small gap between the price at which it buys and the price at which it sells, earned over and over. In return it stands ready to quote both sides at once, which is what keeps trading in an instrument moving.
Checked 31 Oct 2026 · 2 facts
- Market makers earn money from the spread between their buying and selling prices. gov.uk
- Market makers offer both buying and selling prices, providing liquidity that enables trading. nasdaq.com
- 8Short for mintmark: a letter or symbol on a coin that shows which mint made it.
He wants to swap his Philadelphia quarters for ones with a Denver MM.
The seller's photos were too blurry to show the MM, so I passed on the coin.
Note
The letters follow the mint's name, as in a West Point MM, and can carry the side of the coin as well: Bruce Remick wondered in 2009 whether a 1917 half dollar with the obverse MM belonged in a type set.
Checked 2 Nov 2026 · 3 facts
- The example places MM after the mint’s name, West Point. en.wiktionary.org
- Bruce Remick’s cited post dates from 2009. en.wiktionary.org
- Remick questioned including a 1917 half dollar with an obverse mintmark in a type set. en.wiktionary.org
- 9Short for man-month: a unit of work equal to what one person does in one month.
The estimate came to 30 MM, or roughly five developers for six months.
The contract is priced per MM, so extra staff means a bigger bill.
Note
It counts effort rather than calendar time, so 6 MM can be one person for six months or six people for one. In a contract the same letters can also mean a million; a dollar sign in front is the usual clue that money, not work, is being counted.
Checked 31 Oct 2026 · 3 facts
- Man-months measure effort separately from elapsed calendar time. qsm.com
- One person working for six months and six people working for one month each represent six person-months of effort. qsm.com
- MM can denote millions, with $mm identifying millions of dollars. corporatefinanceinstitute.com
- 10Plural of M, short for Monsieur.
- 11Short for Master of Music: a graduate degree in music, usually in performance, composition, or a related field.
- 12Short for moving magnet: a record player cartridge whose needle moves a magnet near fixed coils to create an electrical signal.
- 13Short for Master Mason: a Freemason who has received the third degree, the highest of the basic craft degrees.
- 14Short for Master of Management: a graduate business degree in management, often taken soon after a first degree.
- 15Initialism of maritime mobile.
- 16Short for middle marker: a radio beacon near a runway that signals a plane’s position as it approaches to land.
- 17Short for mounted mint: the condition of an unused stamp that has been mounted with a hinge, leaving the gum on the back disturbed.
- 18Short for mathematical morphology: math methods for studying and changing shapes, especially in digital pictures.
Showing meanings only.
Practice
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