The noun labor has 7 senses (first 2 from tagged texts)
1. (21) labor, labour, toil -- (productive work (especially physical work done for wages); "his labor did not require a great deal of skill")
2. (20) labor, labour, working class, proletariat -- (a social class comprising those who do manual labor or work for wages; "there is a shortage of skilled labor in this field")
3. parturiency, labor, labour, confinement, lying-in, travail, childbed -- (concluding state of pregnancy; from the onset of labor to the birth of a child; "she was in labor for six hours")
4. labor movement, trade union movement, labor -- (an organized attempt by workers to improve their status by united action (particularly via labor unions) or the leaders of this movement)
5. Labour Party, Labour, Labor Party, Labor -- (a political party formed in Great Britain in 1900; characterized by the promotion of labor's interests and the socialization of key industries)
6. Department of Labor, Labor Department, Labor, DoL -- (the federal department responsible for promoting the working conditions of wage earners in the United States; created in 1913)
7. undertaking, project, task, labor -- (any piece of work that is undertaken or attempted; "he prepared for great undertakings")
Overview of verb labor
The verb labor has 3 senses (first 2 from tagged texts)
1. (5) tug, labor, labour, push, drive -- (strive and make an effort to reach a goal; "She tugged for years to make a decent living"; "We have to push a little to make the deadline!"; "She is driving away at her doctoral thesis")
2. (1) labor, labour, toil, fag, travail, grind, drudge, dig, moil -- (work hard; "She was digging away at her math homework"; "Lexicographers drudge all day long")
3. labor, labour -- (undergo the efforts of childbirth)