binding (n.)

mid-13c., "act or action of securing, uniting, etc.," verbal noun from bind (v.). The meaning "thing that binds" is from c. 1300; that of "state of being bound" is from late 14c. The sense of "covering of a book" is recorded from 1640s.

binding (adj.)

late 14c., "serving to bind," past-participle adjective from bind (v.). The meaning "having power to bind" is from 1610s.