up quark

noun

, Physics.

1. the quark having electric charge 2/3 times the elementary charge and strangeness and charm equal to 0.

up quark

/ ŭp /

1. A quark with a charge of +2/3. Its mass is approximately 10 times the electron mass and is the least mass of all quarks.
2. See Table at subatomic particle

Word History and Origins

Origin of up quark¹

First recorded in 1975–80