caution has 9 distinct synonyms spread across 5 of its 5 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 one recorded opposite is incaution.
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.
the trait of being cautious; being attentive to possible danger
“a man of caution”
judiciousness in avoiding harm or danger
“he exercised caution in opening the door”
the trait of being circumspect and prudent
Synonyms, antonyms and the broader and narrower relations for caution come from Princeton University’s WordNet. Full sources and licences.