knocks
n. countable A1 Beginner US //ˈnɑks// UK //nˈɒks// knocks
n. the sounds made when someone hits a hard surface with their hand, usually to get attention. You hear these when someone is at your door.
n. sharp, percussive sounds produced by a hand or object striking a hard surface. Often used in the plural to describe the repeated action of hitting a door to request entry.
I heard three loud knocks at the front door.
The sudden knocks on the window startled the family while they were watching a movie in the dark.
The rhythmic knocks echoing through the empty hallway suggested that someone was testing the structural integrity of the wooden panels rather than seeking admittance.
Usage
Usually appears in the plural when referring to the act of signaling at a door.