semi

[ sem-ee, sem-ahy ]
/ ˈsɛm i, ˈsɛm aɪ /
SEE SYNONYMS FOR semi ON THESAURUS.COM

noun Informal.

semitrailer(def 1).
Often semis. semifinal(def 3).

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Origin of semi

by shortening

Words nearby semi

semenuria, semeru, semester, semester hour, semey, semi, semi-, semi-abstract, semi-bantu, semi-closed anesthesia, semi-independent

Definition for semi (2 of 2)

semi-

a combining form borrowed from Latin, meaning “half,” freely prefixed to English words of any origin, now sometimes with the senses “partially,” “incompletely,” “somewhat”: semiautomatic; semidetached; semimonthly; semisophisticated.

Origin of semi-

Middle English < Latin sēmi-; cognate with Old English sōm-, sām- half (modern dial. sam-), Old High German sāmi-, Sanskrit sāmi-, Greek hēmi-; cf. sesqui-

usage note for semi-

See bi-1.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Words related to semi

wagon, van, car, crate, pickup, rig, jeep, freighter, lorry, buggy, dump, wheels, carryall, apparent, apparently, fake, mock, near, nominal, partly

Example sentences from the Web for semi

British Dictionary definitions for semi (1 of 2)

semi
/ (ˈsɛmɪ) /

noun plural semis

British a semidetached house
short for semifinal
US, Canadian, Australian and NZ short for semitrailer

British Dictionary definitions for semi (2 of 2)

semi-

prefix

halfsemicircle Compare demi- (def. 1), hemi-
partially, partly, not completely, or almostsemiprofessional; semifinal
occurring twice in a specified period of timesemiannual; semiweekly

Word Origin for semi-

from Latin; compare Old English sōm-, sām- half, Greek hēmi-
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

Medical definitions for semi

semi-

pref.

Half:semicanal.
Partial; partially:semiconscious.
Resembling or having some of the characteristics of:semilunar.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for semi

semi-

A prefix that means “half,” (as in semicircle, half a circle) or “partly, somewhat, less than fully,” (as in semiconscious, partly conscious).
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.