to give a blow or push to; strike

to rap sharply with the knuckles, a hard object, etc, esp to capture attention

to make or force by striking

to collide (with)

to bring into a certain condition by hitting or pushing

to criticize adversely; belittle

(of an internal-combustion engine) to emit a characteristic metallic noise as a result of faulty combustion

(of a bearing, esp one in an engine) to emit a regular characteristic sound as a result of wear

to have sexual intercourse with (a person)

the sound of knocking in an engine or bearing

a misfortune, rebuff, or setback

unfavourable criticism

(in cricket) an innings or a spell of batting