'Forthink' definitions:

Definition of 'Forthink'

From: GCIDE

Forthink \For*think"\, v. t. To repent; to regret; to be sorry for; to cause regret. [Obs.] "Let it forthink you." --Tyndale. [1913 Webster]
That me forthinketh, quod this January. --Chaucer. [1913 Webster]