Middle English word forsayen comes from Old English for-, Old English secgan (To say, tell, declare.), Old English seċġan

Detailed word origin of forsayen

Dictionary entry	Language	Definition
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.
secgan	Old English (ang)	To say, tell, declare.
seċġan	Old English (ang)
forseċġan	Old English (ang)
forsecgan	Old English (ang)	To say against, accuse, deny; say away.. To say wrongly, say ill.
forsayen	Middle English (enm)

Words with the same origin as forsayen