The Collaborative International Dictionary of English v.0.48:

Laborer \La"bor*er\, n. [Written also labourer.]
   One who labors in a toilsome occupation; a person who does
   work that requires strength rather than skill, as
   distinguished from that of an artisan.
   [1913 Webster]

WordNet (r) 3.0 (2006):

laborer
    n 1: someone who works with their hands; someone engaged in
         manual labor [syn: laborer, manual laborer, labourer,
         jack]

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "laborer":
   blue-collar worker, bourgeoisie, breadwinner, casual,
   casual laborer, common laborer, common people, common run,
   common sort, commonage, commonality, commonalty, commoners,
   commons, day laborer, drudge, employee, factory worker, flunky,
   free lance, free-lancer, full-time worker, hand, industrial worker,
   jobber, jobholder, laborers, laboring man, linendrapers,
   lower classes, lower middle class, lower orders,
   lumpen proletariat, menial, middle class, middle orders, migrant,
   moiler, navvy, office temporary, operative, ordinary people,
   peasantry, plain folks, plain people, proletarian, proletariat,
   rank and file, roustabout, salaried worker, self-employed person,
   servant, shopkeepers, small tradesmen, stiff, temporary,
   the lower cut, the other half, the third estate, toiler, toilers,
   toiling class, upper middle class, vulgus, wage earner, wage slave,
   wageworker, worker, workgirl, workhand, working class,
   working girl, working people, workingman, workingwoman, workman