bitter lemon noun

A lemon-flavoured soft drink

bitter orange noun

The Seville orange, bitter when ripe, used for making marmalade, etc

bittˈer-pit noun

A disease of apples, etc, characterized by brown spots and depressions

bittˈer-root noun

An American xerophytic plant (Lewisia rediviva)

bittˈer-spar noun

Dolomite

bittˈersweet noun

1. The woody nightshade (Solanum dulcamara), whose stems when chewed taste first bitter, then sweet
2. An apple that tastes both sweet and bitter (Shakespeare)
3. A mixture of sweet and bitter (also figurative; also adjective)

bitter vetch see vetch

bittˈerwood noun

Any of various trees, esp of the family Simarubaceae

a bitter pill to swallow

Something which is difficult or unpleasant to accept, such as an unwelcome fact

the bitter end see bitt