Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Homo- \Ho"mo-\ A combining form from Gr. "omo`s, one and the same, common, joint.
Douglas Harper's Etymology Dictionary
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 (cognates: Sanskrit samah "even, the same," Lithuanian similis "like," Gothic sama "the same," samana "together;" see same).
Etymology 1 pre. same Etymology 2
pre. of or pertaining to homosexuals or homosexuality Etymology 3
pre. (context organic chemistry English) Used to form the names of compounds derived from simpler ones by addition of a methylene group