Entry 3 senses · 2 variants Webster, 1913 Knock-off · Knock·-off · IPA n. a. 01 n. Act or place of knocking off; that which knocks off; 1. Act or place of knocking off; that which knocks off;(Mach.) 2. A knockoff. See: knockoff 02 a. That knocks off; of or pertaining to knocking off. 1. That knocks off; of or pertaining to knocking off.