knock (Noun) — The sound of knocking (as on a door or in an engine or bearing). ex. "the knock grew louder"
knock (Noun) — Negative criticism.
knock (Noun) — A vigorous blow. ex. "the sudden knock floored him"
knock (Noun) — A bad experience. ex. "the school of hard knocks"
knock (Noun) — The act of hitting vigorously. ex. "he gave the table a knock"
knock (Verb) — Deliver a sharp blow or push. ex. "He knocked the glass clear across the room"
knock (Verb) — Rap with the knuckles. ex. "knock on the door"
knock (Verb) — Collide with force or violence. ex. "My car knocked into the tree"
knock (Verb) — Make light, repeated taps on a surface. ex. "he was knocking his fingers on the table impatiently"
knock (Verb) — Sound like a car engine that is firing too early. ex. "The car knocked when the ignition was too far retarded"
knock (Verb) — Find fault with; express criticism of; point out real or perceived flaws. ex. "Don't knock the food--it's free"