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homo-

  1. a combining form appearing in loanwords from Greek, where it meant “same” (homology); on this model, used in the formation of compound words (homomorphic).
Also especially before a vowel, hom-.

Origin of homo-

< Greek, combining form of homós one and the same; akin to Sanskrit sama-; see same
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for homo-

homo-

combining form
  1. being the same or likehomologous; homosexual Compare hetero-

Word Origin for homo-

via Latin from Greek, from homos same
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 homo-
1

word-forming element meaning "same, the same, equal, like," before vowels hom-, from Greek homos "one and the same," also "belonging to two or more jointly," from PIE *somos (cf. Sanskrit samah "even, the same," Lithuanian similis "like," Gothic sama "the same," samana "together;" see same).

2

word-forming element meaning "homosexual," abstracted since early 20c. from homosexual, and ultimately identical to homo- (1).

Online Etymology Dictionary, © 2010 Douglas Harper
homo- in Medicine

homo-

pref.
  1. Same; like:homotype.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
homo- in Science

homo-

  1. A prefix meaning “same,” as in homogamous, having the same kind of flower.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.