Wordnet 3.0
NOUN (1)
1. 
 any division of quantity accepted as a standard of measurement or exchange; 
- Example: "the dollar is the United States unit of currency"- Example: "a unit of wheat is a bushel"- Example: "change per unit volume"[syn: unit of measurement, unit]
WordNet (r) 3.0 (2006):
unit of measurement
    n 1: any division of quantity accepted as a standard of
         measurement or exchange; "the dollar is the United States
         unit of currency"; "a unit of wheat is a bushel"; "change
         per unit volume" [syn: unit of measurement, unit]