Other forms: jerks, jerking, jerked
To jerk is to move with one short sharp pull. The train jerked forward. He jerked his head towards the door.
The noun is that movement — a jerk of the wrist, the bus started with a jerk — and in weightlifting the clean and jerk is one of the two Olympic lifts. In American informal English a jerk is an unpleasant person, and that use is now understood everywhere though it stays American in flavour. Note jerk chicken, which is Jamaican and comes from an entirely unrelated word, and knee-jerk, meaning an automatic reaction with no thought behind it.
1verbjerkTo move with a short sharp pull.
“The rope jerked and he lost his footing.”
2nounmovementA short sharp movement.
“The lift stopped with a jerk.”
3nounuseIn American informal use, an unpleasant person.
“He was being a complete jerk about it.”
Too few real examples of this word to estimate which sense is commonest.
jerk is a sharp movement.
Middle English
yerk — sudden motion
English, today
jerk
Probably from Middle English yerk (“sudden motion”) and Middle English yerkid (“tightly pulled”), from Old English ġearc (“ready, active, quick”) and Old English ġearcian (“to prepare, make ready, procure, furnish, supply”). Cognate with Scots yerk (“to jerk”). Related also to yare (“ready”).
Etymology from Wiktionary, CC BY-SA