even has 11 distinct synonyms spread across 9 of its 14 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 2 recorded opposites are odd, uneven.
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.
divisible by two
equal in degree or extent or amount; or equally matched or balanced
“even amounts of butter and sugar”
being level or straight or regular and without variation as e.g. in shape or texture; or being in the same plane or at the same height as something else (i.e. even with)
“an even application of varnish”
the latter part of the day (the period of decreasing daylight from late afternoon until nightfall)
“he enjoyed the evening light across the lake”
3 of the 14 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 even.
Synonyms, antonyms and the broader and narrower relations for even come from Princeton University’s WordNet. Full sources and licences.