An oar that is worked with great effort. / (chiefly US, figuratively, by extension) The part of a task that requires the greatest effort to achieve.

(American spelling) Requiring a great deal of work, especially physical and manual effort versus capital.

(US), (Canada) The holiday marking the unofficial end of summer, held on the first Monday in September. / An annual holiday held on May 1 to celebrate the economic and social achievements of workers.

(US) Alternative spelling of labour force

(American spelling) Work done by hand or using basic tools rather than by machines; usually physically demanding but (sometimes derogatory) unskilled labor.

(Canada, US) A continuous association of wage-earners for the purpose of maintaining or improving the conditions of their employment; a trade union.

plural of labor union

(American spelling) Work which one is compelled to perform against one's will, especially in a condition of involuntary servitude as a prisoner or slave.

(American spelling) Alternative spelling of child labour

(economics) The market consisting of the supply of unemployed workers in relation to the demand for them.