English
knockmeter
From knock + -meter.
Formed from knock + -meter
Proto-Indo-European *gnew- ‘to squeeze, pinch, ball up’
…
Proto-Germanic *knukōną ‘to knock’
Proto-West Germanic *knokōn
Old English cnocian ‘to knock, pound on, beat’
Middle English knokken
English knock
Today it means
noun A device for measuring the intensity of engine knock.
Language periods are conventional ranges, not dates for this word.
Etymograph / knockmeter