gruelling

from WordNet (r) 3.0 (2006)

gruelling
    adj 1: characterized by effort to the point of exhaustion;
           especially physical effort; "worked their arduous way up
           the mining valley"; "a grueling campaign"; "hard labor";
           "heavy work"; "heavy going"; "spent many laborious hours
           on the project"; "set a punishing pace" [syn: {arduous},
           {backbreaking}, {grueling}, {gruelling}, {hard}, {heavy},
           {laborious}, {operose}, {punishing}, {toilsome}]

from The Collaborative International Dictionary of English v.0.48

grueling \grueling\, gruelling \gruelling\adj.
   1. characterized by toilsome effort; requiring extreme
      physical or mental effort; as, a grueling campaign.

   Syn: arduous, backbreaking, back-breaking, exhausting,
        gruelling, hard, heavy, laborious, labourious,
        punishing, slavish, strenuous, toilsome.
        [WordNet 1.5]

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