source has 11 distinct synonyms spread across 6 of its 11 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 sink.
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 place where something begins, where it springs into being
“the Italian beginning of the Renaissance”
a document (or organization) from which information is obtained
“the reporter had two sources for the story”
anything that provides inspiration for later work
(technology) a process by which energy or a substance enters a system
“a heat source”
a publication (or a passage from a publication) that is referred to
“he carried an armful of references back to his desk”
specify the origin of
“The writer carefully sourced her report”
Synonyms, antonyms and the broader and narrower relations for source come from Princeton University’s WordNet. Full sources and licences.