"one-fourth of a gallon," early 14c., from Old French quarte "a fourth part" (13c.), from Latin quarta (pars), from fem. of quartus "the fourth," related to quattuor "four," from PIE root *kewtwor- (see four). Cf. Latin quartarius "fourth part," also the name of a small liquid measure (the fourth part of a sextarius), which was about the same as an English pint.
Abbr. q., qt, qt.
A unit of volume or capacity in the U.S. Customary System, used in liquid measure, equal to 2 pints or 32 ounces (0.946 liter).
A unit of volume or capacity in the U.S. Customary System, used in dry measure, equal to 1.101 liters.