Wordnet 3.0
ADJECTIVE (1)
1. 
 doing arduous or unpleasant work; 
- Example: "drudging peasants"- Example: "the bent backs of laboring slaves picking cotton"- Example: "toiling coal miners in the black deeps"[syn: drudging, laboring, labouring, toiling]
WordNet (r) 3.0 (2006):
labouring
    adj 1: doing arduous or unpleasant work; "drudging peasants";
           "the bent backs of laboring slaves picking cotton";
           "toiling coal miners in the black deeps" [syn:
           drudging, laboring, labouring, toiling]