(figuratively) Ellipsis of bitter pill to swallow. / Used other than figuratively or idiomatically: see bitter, pill.

A citrus tree of the species Citrus ×aurantium, also called Citrus aurantium. / A citrus tree of the species Citrus limetta. / The fruit of these species.

plural of bitter melon

A vine, Momordica charantia, which produces a bitter, though when properly prepared edible, fruit. / (Australia) A similar fruit-bearing vine, Citrullus lanatus (Citroides Group).

plural of bitter end

dolomite

Synonym of bitter melon

plural of bitter gourd

plural of best bitter

(UK) A bitter ale of a strength between 4.2% and 4.7% ABV.