From The Collaborative International Dictionary of English v.0.48 [gcide]:
Envenom \En*ven"om\, v. t. [imp. & p. p. Envenomed; p. pr. &
vb. n. Envenoming.] [OE. envenimen, F. envenimer; pref. en-
(L. in) + F. venin poison. See Venom.]
1. To taint or impregnate with venom, or any substance
noxious to life; to poison; to render dangerous or deadly
by poison, as food, drink, a weapon; as, envenomed meat,
wine, or arrow; also, to poison (a person) by impregnating
with venom.
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Alcides . . . felt the envenomed robe. --Milton.
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O, what a world is this, when what is comely
Envenoms him that bears it! --Shak.
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2. To taint or impregnate with bitterness, malice, or hatred;
to imbue as with venom; to imbitter.
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The envenomed tongue of calumny. --Smollett.
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On the question of slavery opinion has of late years
been peculiarly envenomed. --Sir G. C.
Lewis.
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From WordNet (r) 3.0 (2006) [wn]:
envenom
v 1: cause to be bitter or resentful; "These injustices
embittered her even more" [syn: embitter, envenom,
acerbate]
2: add poison to; "Her husband poisoned her drink in order to
kill her" [syn: poison, envenom]