sanely has 2 distinct synonyms spread across 1 of its 2 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 insanely.
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.
with good sense or in a reasonable or intelligent manner
“he acted sensibly in the crisis”
in a sane or lucid manner
“she is behaving rather sanely these days even though we know she is schizophrenic”
Synonyms, antonyms and the broader and narrower relations for sanely come from Princeton University’s WordNet. Full sources and licences.