kilo

¹ American  

[kee-loh, kil-oh] / ˈki loʊ, ˈkɪl oʊ /

noun

plural

kilos

1. kilogram.

2. kilometer.

3. (a word used in communications to represent the letterK. )

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kilo- ² American  

1. a Greek combining form meaning “thousand,” introduced from French in the nomenclature of the metric system (kiloliter ); on this model, used in the formation of compound words in other scientific measurements (kilowatt ).

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kilo ¹ British  

/ ˈkiːləʊ /

noun

1. communications a code word for the letter k

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kilo- ² British  

prefix

1.  k.  denoting 10³ (1000)

   kilometre

2. (in computer technology) denoting 2 ¹⁰ (1024): kilobyte: in computer usage, kilo- is restricted to sizes of storage (e.g. kilobit ) when it means 1024; in other computer contexts it retains its usual meaning of 1000

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kilo ³ British  

/ ˈkiːləʊ /

noun

1. short for kilogram kilometre

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kilo– Scientific  

1. A prefix that means:

2. One thousand, as in kilowatt, one thousand watts.

3. 2 ¹⁰ (that is, 1,024), which is the power of 2 closest to 1,000, as in kilobyte.

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Usage

What does kilo- mean? Kilo- is a combining form used like a prefix meaning “thousand.” It is often used in units of measure.Kilo- comes from Greek chī́lioi, meaning “a thousand.” The Latin translation of chī́lioi is mille, “a thousand,” which is the source of English terms such as millennium and millipede. To learn more, check out our entries for both words.

Etymology

Origin of kilo¹

First recorded in 1865–70; shortened form

Origin of kilo-²

< French, representing Greek chī́lioi a thousand

Example Sentences

A child's shirt for example costs the equivalent of between $15 to $30, while a kilo of chocolates can be even pricier.

From Barron's • Mar. 17, 2026

"Just two months ago, beef was 7m rials per kilo," says Mina, a 44-year-old mother of two in Tehran.

From BBC • Feb. 26, 2026

A kilo of unshelled pistachios has surged fourfold month-on-month since mid-January.

From Barron's • Jan. 20, 2026

"In these two-and-a-half months I haven't loaded even a single kilo of cargo. Work has come to a standstill," he said.

From Barron's • Jan. 4, 2026

I thought about the kilo of sugar he’d tried to stash under his shirt.

From "The Poisonwood Bible" by Barbara Kingsolver