1. (noun)knock, knocking the sound of knocking (as on a door or in an engine or bearing)
"the knocking grew louder"
2. (noun)knock, roast negative criticism
3. (noun)knock, bash, bang, smash, belt a vigorous blow
"the sudden knock floored him"; "he took a bash right in his face"; "he got a bang on the head"
4. (noun)knock a bad experience
"the school of hard knocks"
5. (noun)knock, belt, rap, whack, whang the act of hitting vigorously
"he gave the table a whack"
6. (verb)knock, strike hard deliver a sharp blow or push :"He knocked the glass clear across the room"
7. (verb)knock rap with the knuckles "knock on the door"
8. (verb)bump, knock knock against with force or violence "My car bumped into the tree"
9. (verb)tap, rap, knock, pink make light, repeated taps on a surface "he was tapping his fingers on the table impatiently"
10. (verb)pink, ping, knock soundlike a car engine that is firing too early
"the car pinged when I put in low-octane gasoline"; "The car pinked when the ignition was too far retarded"
11. (verb)knock, criticize, criticise, pick apart findfault with; expresscriticism of; point out real or perceived flaws
"The paper criticized the new movie"; "Don't knock the food--it's free"
Definition of 'knock'
