Knock-on effect etymology in English

Etymology Blog

English word knock-on effect comes from English effect, English knock-on

Dictionary entry	Language	Definition
effect	English (en)	To make or bring about; to implement. (filmology) An illusion produced by technical means (as in "special effect"). (obsolete) Manifestation; expression; sign.. (obsolete) Reality; actual meaning; fact, as distinguished from mere appearance.. (physics, psychology, etc.) A scientific phenomenon, usually named after its discoverer.. (sound engineering) An alteration, or device for producing an [...]
knock-on	English (en)	(chiefly, UK) Resulting as an indirect effect.. (rugby) A foul in which a player knocks the ball forward.
knock-on effect	English (en)	(British) A secondary, often unintended effect; a repercussion, chain reaction.

Knock-on effect etymology