yea (adv.) Look up yea at Dictionary.com
Old English gea (West Saxon), ge (Anglian) "so, yes," from Proto-Germanic *ja-, *jai-, a word of affirmation (cognates: German, Danish, Norwegian, Swedish ja), from PIE *yam-, from pronomial stem *i- (see yon). As a noun, "affirmation, affirmative vote," from early 13c.