knocking
UK: ˈnɒkɪŋ | US: ˈnɑːkɪŋ
n. the sound produced by striking a surface, typically a door, to attract attention
vt. present participle of "knock": to strike a surface noisily, often to signal arrival
The word "knock" originates from Old English cnocian, meaning "to strike or pound," likely of imitative origin (echoing the sound of hitting). The -ing suffix is a productive English morpheme forming present participles or gerunds. Together, "knocking" retains the core action of striking while grammatically marking continuity or nominalization.
She heard a loud knocking at the door late at night.
The mechanic is knocking on the engine to check for issues.
Persistent knocking interrupted his concentration.
The sound of knocking branches against the window was eerie.
He apologized for knocking over the vase accidentally.