1803 (transitive) "to breed by crossing species or varieties," from inter- + breed (v.). Intransitive sense of "procreate with one of a different species" is from 1825. Related: Interbred; interbreeding.
word-forming element used freely in English, "between, among, during," from Latin inter (prep., adv.) "among, between, betwixt, in the midst of" (also used extensively as a prefix), from PIE *enter "between, among" (source also of Sanskrit antar, Old Persian antar "among, between," Greek entera (plural) "intestines," Old Irish eter, Old Welsh ithr "among, between," Gothic undar, Old English under "under"), a comparative of root *en "in."
A living prefix in English from 15c. and used with Germanic as well as Latinate words. Spelled entre- in French; most words borrowed into English in that form were re-spelled 16c. to conform with Latin except entertain, enterprise. In Latin, spelling shifted to intel- before -l-, hence intelligence, etc.
Old English bredan "bring (young) to birth, procreate," also "cherish, keep warm," from West Germanic *brodjan (source also of Old High German bruoten, German brüten "to brood, hatch"), from *brod- "fetus, hatchling," from PIE root *bhreu- "to boil, bubble, effervesce, burn." The etymological notion is incubation, warming to hatch.
Intransitive sense "come into being" is from c. 1200; that of "beget or bear offspring" is from mid-13c. Of livestock, etc., "procure by the mating of parents and rear for use," mid-14c. Sense of "grow up, be reared" (in a clan, etc.) is late 14c.; meaning "form by education" is from mid-15c. Related: Bred; breeding.
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Harper, D. (n.d.). Etymology of interbreed. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/interbreed