n.
Pronunciation: ' kwo ̇ rk, ' kwärk
Function: noun
Etymology: coined by Murray Gell-Mann
Date: 1964
: any of several elementary particles that are postulated to come in pairs (as in the up and down varieties) of similar mass with one member having a charge of +2/3 and the other a charge of -1/3 and are held to make up hadrons