Definition of "envenom"

As when Alcides from Oealia Crown’dWith conqueſt, felt th’ envenom’d robe, and toreThrough pain up by the roots Theſſalian Pines […]

1667, John Milton, “Book II”, in Paradise Lost. […], London: […] [Samuel Simmons], […]; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873,

Nay, was it I who wooed thee to this breast, / Which like a serpent thou envenomest / As in repayment of the warmth it lent?

1818–1819, Percy Bysshe Shelley, “Julian and Maddalo; a Conversation”, in Mary W[ollstonecraft] Shelley, editor, Posthumous Poems of Percy Bysshe Shelley, London: […] [C. H. Reynell] for John and Henry L[eigh] Hunt, […], published 1824, page 18

Ah dearest, whoso sucks a poisoned woundEnvenoms his own veins!

1833, Robert Browning, Pauline

The Kayans of Central Borneo ascribe souls to the trees which yield the poison they use to envenom their arrows.

1890, James George Frazer, The Golden Bough, volume 2, page 17

Oh what a world is this, when what is comelyEnuenoms him that beares it?

c. 1598–1600 (date written), William Shakespeare, “As You Like It”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene iii], page 190, column 2