WordNet sense 1 (concluding state of pregnancy; from the onset of labor to the birth of a child):

confinement, lying-in, travail, labour, childbed, parturiency

WordNet sense 2 (an organized attempt by workers to improve their status by united action (particularly via labor unions) or the leaders of this movement):

labor movement, trade union movement

WordNet sense 3 (a political party formed in Great Britain in 1900; characterized by the promotion of labor's interests and the socialization of key industries):

labor party, Labour Party

WordNet sense 4 (a social class comprising those who do manual labor or work for wages):

proletariat

WordNet sense 5 (the federal department responsible for promoting the working conditions of wage earners in the United States; created in 1913):

dol, Department of Labor, Labor Department

WordNet sense 6 (work hard):

dig, drudge, grind, moil, toil

WordNet sense 7 (strive and make an effort to reach a goal):

drive, push, tug

WordNet sense 8 (any piece of work that is undertaken or attempted):

project, task, undertaking, project