knock
intransitive verbTo strike with a hard blow.
intransitive verbTo affect in a specified way by striking hard.
intransitive verbTo cause to be displaced or unengaged; force.
intransitive verbTo cause to collide.
intransitive verbTo produce by hitting or striking.
intransitive verbTo find fault with; criticize.
intransitive verbTo strike a sharp audible blow or series of blows, as on a door.
intransitive verbTo collide with something.
intransitive verbTo make a pounding or clanking noise.
nounAn instance of striking or colliding.