1620s, "to cast as seed," from inseminatus, past participle of Latin inseminare "to sow, implant," from in- "in" (from PIE root *en "in") + semen (genitive semenis) "seed" (from PIE root *sē- "to sow"). Meaning "to impregnate with semen" is attested from 1897.
It has seemed necessary, therefore, to make a distinction between the introduction of seminal fluid into the female generative organs of animals and the subsequent possible fertilisation of their ova, and for that purpose I have used the word "inseminate," which can thus be applied to animals in precisely the same way as the word "pollenate" is applied by some botanists to denote the placing of pollen on the stigma of a plant. [Walter Heape, "The artificial Insemination of Mammals," Proceedings of the Royal Society of London, vol. lxi, 1897]
Related: Inseminated; inseminating.
Old English impe, impa "young shoot, graft," from impian "to graft," probably an early Germanic borrowing from Vulgar Latin *imptus, from Late Latin impotus "implanted," from Greek emphytos, verbal adjective formed from emphyein "implant," from em- "in" + phyein "to bring forth, make grow," from PIE root *bheue- "to be, exist, grow." Compare Swedish ymp, Danish ympe "graft."
The sense of the word has shifted from plants to people, via the meaning "child, offspring" (late 14c., now obsolete), from the notion of "newness." The current meaning "little devil" is attested from 1580s, from common pejorative phrases such as imp of Satan. The extension from this to "mischievous or pert child" (1640s) unconsciously turns the word back toward its Middle English sense.
Suche appereth as aungelles, but in very dede they be ymps of serpentes. [Wynkyn de Worde, "The Pilgrimage of Perfection," 1526]