Middle English word forspeken comes from Old English sprecan (To speak.), Old English for-

Detailed word origin of forspeken

Dictionary entry	Language	Definition
sprecan	Old English (ang)	To speak.
for-	Old English (ang)	Forming verbs from verbs with various senses especially ‘wrongly, away from, astray, abstention, prohibition, perversion, destruction’. Used to create intensified adjectives and verbs from other adjectives and verbs, with the sense of completely or fully. Compare Modern English use of up. Very.
forsprecan	Old English (ang)	To deny; gainsay; forsay.. To speak against, speak ill of, denounce.. To speak amiss or wrongly.
forspeken	Middle English (enm)

Words with the same origin as forspeken