For-, [AS. for-; akin to D. & G. ver-, OHG. fir-, Icel. for-, Goth. fra-, cf. Skr. parā- away, Gr. beside, and E. far, adj. Cf. Fret to rub.].
A prefix to verbs, having usually the force of a negative or privative. It often implies also loss, detriment, or destruction, and sometimes it is intensive, meaning utterly, quite thoroughly, as in forbathe. [1913 Webster]