Origin of unit

1570; coined by John Dee as a translation of Greek mónas (previously rendered as unity); perhaps influenced by digit
Related formsin·ter·u·nit, adjectivemul·ti·u·nit, adjectivesub·u·nit, nounsu·per·u·nit, noun


Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for unit

Contemporary Examples of unit

Historical Examples of unit

  • Neither evolution nor involution will ever effect the value of a unit.

  • At all events, it is as impossible to demonstrate the non-existence of the one unit as the other.

  • Values are reckoned in “skins”—­that is, a “skin” is the unit of value.

  • I saw myself now as part of the whole, a unit in the sum of a life which interested me.

    The First Violin

    Jessie Fothergill

  • And, for the size-change, a normal diameter, Unit 1—and then up into thousands.

    The World Beyond

    Raymond King Cummings

British Dictionary definitions for unit



a single undivided entity or whole
any group or individual, esp when regarded as a basic element of a larger whole
a mechanical part or integrated assembly of parts that performs a subsidiary functiona filter unit
a complete system, apparatus, or establishment that performs a specific functiona production unit
a subdivision of a larger military formation
Also called: unit of measurement A standard amount of a physical quantity, such as length, mass, energy, etc, specified multiples of which are used to express magnitudes of that physical quantitythe second is a unit of time
the amount of a drug, vaccine, etc, needed to produce a particular effect
a standard measure used in calculating alcohol intake and its effect
  1. (usually plural)the first position in a place-value counting system, representing a single-digit numberin the decimal system the number 27 has 7 units and 2 tens
  2. (modifier)having a value defined as one for the systemunit vector
Also called: unit set maths logic a set having a single member
short for home unit
short for stock unit
NZ a self-propelled railcar

Word Origin for unit

C16: back formation from unity, perhaps on the model of digit


abbreviation for

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for unit

1560s, "single number regarded as an undivided whole," alteration of unity on the basis of digit. Popularized in John Dee's English translation of Euclid, to express Greek monas (Dee says unity formerly was used in this sense). Meaning "single thing regarded as a member of a group" is attested from 1640s. Extended sense of "a quantity adopted as a standard of measure" is from 1738. Sense of "group of wards in a hospital" is attested from 1893.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for unit




An entity regarded as an elementary structural or functional constituent of a whole.
A precisely specified quantity in terms of which the magnitudes of other quantities of the same kind can be stated.
The quantity of a serum, drug, or other agent necessary to produce a specific effect.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.