Micro-

Pronunciation

Origin

From Ancient Greek μικρός (mikros, "small").

Prefix

1. Very small.organism → microorganism
2. (metric units) One millionth.gram → microgram

Usage notes

(one millionth) Officially, micro- is abbreviated as µ- (the Greek letter mu); for example, one second is 1s, so one microsecond is 1µs. However, for many purposes this is inconvenient, so writers often use either u- (for its similar appearance to µ-) or mc-, producing, for example, 1um (one micrometer) and 1mcg (one microgram).

Antonyms

• (very small) mega-, macro-

Derived terms