WordNet (r) 3.0 (2006):

roughneck
    n 1: a cruel and brutal fellow [syn: bully, tough,
         hooligan, ruffian, roughneck, rowdy, yob, yobo,
         yobbo]

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "roughneck":
   Babbitt, Philistine, arriviste, boor, boorish, bounder, bourgeois,
   bruiser, bullyboy, cad, carlish, churl, churlish, cloddish, clown,
   clownish, epicier, goon, gorilla, groundling, gun, gunsel,
   guttersnipe, hatchet man, hellion, holy terror, hood, hoodlum,
   hooligan, hooliganish, ill-bred fellow, looby, loobyish, lout,
   loutish, low fellow, lubberly, lumpish, mucker, mug, mugger,
   muscle man, nouveau riche, parvenu, peasant, plug-ugly, punk,
   raffish, ribald, rodman, rough, rowdy, rowdyish, ruffian,
   ruffianly, strong-arm man, terror, torpedo, tough, trigger man,
   ugly customer, upstart, vulgarian, vulgarist, yahoo, yokel,
   yokelish