A bak to walken inne by daylight.
Chaucer.
Behind one's back, when one is absent; without one's knowledge; as, to ridicule a person behind his back. -- Full back, Half back, Quarter back (Football), players stationed behind those in the front line. -- To be or lie on one's back, to be helpless. -- To put, or get, one's back up, to assume an attitude of obstinate resistance (from the action of a cat when attacked). [Colloq.] -- To see the back of, to get rid of. -- To turn the back, to go away; to flee. -- To turn the back on one, to forsake or neglect him.
Back, a. 1. Being at the back or in the rear; distant; remote; as, the back door; back settlements.