sb. and a.
A. sb. A contrivance for knocking something off, or point at which something is knocked off.
1875. Knight, Dict. Mech., 1240/1. Knock off (Knitting-machine), the piece which, at the proper moment, removes the loops from the tier of needles.
1883. Gresley, Gloss. Coal Mining Terms, Knock off (1) The point upon an engine plane at which the set is disconnected from the rope, or where a jockey comes into play. (2) A joint for disconnecting the bucket sword from the pump rods.
B. adj. as in knock-off time, time to ‘knock off’ or leave off work.
1899. F. T. Bullen, Log Sea-waif, 108. It was ‘knock-off’ time.
