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