knock
1. knock \'na:k\ vb [ME knoken, fr. OE cnocian; akin to MHG knochen to
press] 1: to strike something with a sharp blow 2: to collide with
something 3a: BUSTLE 3b: WANDER 4a: to make a pounding noise 4b: to
have engine knock 5: to find fault 1a1: to strike sharply 1a2: to drive,
force, or make by so striking 1b: to set forcibly in motion with a blow
2: to cause to collide 3: to find fault with
2. knock n 1a: a sharp blow 1b1: a severe misfortune or hardship 1b2:
SETBACK, REVERSAL 2a: a pounding noise 2b: a sharp metallic noise caused
by abnormal ignition in an automobile eng ine 3: a harsh and often petty
criticism