labor has 28 distinct synonyms spread across 10 of its 10 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. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
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.
a social class comprising those who do manual labor or work for wages
“there is a shortage of skilled labor in this field”
concluding state of pregnancy; from the onset of contractions to the birth of a child
“she was in labor for six hours”
an organized attempt by workers to improve their status by united action (particularly via labor unions) or the leaders of this movement
a political party formed in Great Britain in 1900; characterized by the promotion of labor's interests and formerly the socialization of key industries
the federal department responsible for promoting the working conditions of wage earners in the United States; created in 1913
any piece of work that is undertaken or attempted
“he prepared for great undertakings”
work hard
Synonyms, antonyms and the broader and narrower relations for labor come from Princeton University’s WordNet. Full sources and licences.
“She was digging away at her math homework”