worker has 4 distinct synonyms spread across 2 of its 4 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 nonworker.
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.
Synonyms, antonyms and the broader and narrower relations for worker come from Princeton University’s WordNet. Full sources and licences.
a member of the working class (not necessarily employed)
“workers of the world--unite!”
sterile member of a colony of social insects that forages for food and cares for the larvae
a person who acts and gets things done
“he's a principal actor in this affair”