freelance has 7 distinct synonyms spread across 3 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 salaried.
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.
working for yourself
a writer or artist who sells services to different employers without a long-term contract with any of them
work independently and on temporary contracts rather than for a long-term employer
Synonyms, antonyms and the broader and narrower relations for freelance come from Princeton University’s WordNet. Full sources and licences.