n.1 a an individual thing, person, or group regarded as single and complete, esp. for purposes of calculation. b each of the (smallest) separate individuals or groups into which a complex whole may be analysed (the family as the unit of society).
2 a quantity chosen as a standard in terms of which other quantities may be expressed (unit of heat; SI unit; mass per unit volume).
3 Brit. the smallest share in a unit trust.
4 a device with a specified function forming part of a complex mechanism.
5 a piece of furniture for fitting with others like it or made of complementary parts.
6 a group with a special function in an organization.
7 a group of buildings, wards, etc., in a hospital.
8 the number 'one'.
Phrases and idioms:
unit cell Crystallog. the smallest repeating group of atoms, ions, or molecules in a crystal. unit cost the cost of producing one item of manufacture. unit-holder Brit. a person with a holding in a unit trust. unit price the price charged for each unit of goods supplied. unit trust Brit. an investment company investing combined contributions from many persons in various securities and paying them dividends in proportion to their holdings.
Etymology: L unus, prob. after DIGIT