quark: Pronunciation Key (kwôrk, kwärk)n.
Any of a group of six elementary particles having electric charges of a magnitude one-third or two-thirds that of the electron, regarded as constituents of all hadrons.
quirk: Pronunciation Key (kwûrk)n.
A peculiarity of behavior; an idiosyncrasy: “Every man had his own quirks and twists” (Harriet Beecher Stowe).
Main Entry: jerk
Pronunciation: 'j&rk
Function: noun
Etymology: probably alteration of yerk
Date: 1575
1 : a single quick motion of short duration
2 a : jolting, bouncing, or thrusting motions b : a tendency to produce spasmodic motions
3 a : an involuntary spasmodic muscular movement due to reflex action b plural : involuntary twitchings due to nervous excitement
4 : an annoyingly stupid or foolish person