Wiktionary
turnest
vb. (context archaic English) Second-person singular present simple form of '''turn'''
Usage examples of "turnest".
And anon there appeared the Sangreal unto the white knights, but thou was so feeble of good belief and faith that thou mightest not abide it for all the teaching of the good man, but anon thou turnest to the sinners, and that caused thy misadventure that thou should'st know good from evil and vain glory of the world, the which is not worth a pear.
Go now, but if thou turnest back, even once, thou shalt return here and never leave.