half-gallon

[ haf-gal-uh n, hahf- ]
/ ˈhæfˈgæl ən, ˈhɑf- /

noun

a half of a gallon, equal to 2 quarts (1.9 liters).

adjective

holding or consisting of two quarts.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for half-gallon