knocking
UK[ˈnɒkɪŋ]US[ˈnɑːkɪŋ]
n
the action of striking a surface noisily to attract attention.
n
a repetitive sound caused by something striking or tapping against a surface, especially within an engine.
Etymology
the word 'knocking' originates from the old english verb 'cnocian', meaning to strike or pound. this term is believed to be of onomatopoeic origin, imitating the sharp, percussive sound of a blow. it is part of a family of germanic words with similar sounds and meanings, such as middle dutch and middle low german 'knocken'. the modern participle form 'knocking' retains this core sense of producing a sharp, audible impact, whether by hand on a door or by mechanical parts within an engine.
Analysis
the word is a simplex form derived from the old english verb 'cnocian'. it is not productively formed from smaller, independent morphemes in modern english.
Examples
there was a loud knocking at the front door.
i can hear a strange knocking sound coming from the car's engine.
the constant knocking from the construction site made it hard to concentrate.