straight has 16 distinct synonyms spread across 12 of its 21 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 3 recorded opposites are crooked, curly, curved.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
(of hair) having no waves or curls
“her naturally straight hair hung long and silky”
no longer coiled
free from curves or angles
“a straight line”
rigidly conventional or old-fashioned
a person having a sexual orientation to persons of the opposite sex
a poker hand with 5 consecutive cards (regardless of suit)
5 of the 21 recorded senses carry no synonym, antonym or related term, so they are not shown above. Every sense, with its definition and examples, is on the full entry for straight.
Synonyms, antonyms and the broader and narrower relations for straight come from Princeton University’s WordNet. Full sources and licences.
a straight segment of a roadway or racecourse