'labourious' definitions:

Definition of 'labourious'

From: GCIDE
  • labourious \labourious\ adj.
  • 1. characterized by toilsome effort; same as laborious; -- British spelling. [Chiefly Brit.]
  • Syn: arduous, backbreaking, back-breaking, grueling, gruelling, hard, heavy, laborious, punishing, slavish, strenuous, toilsome. [WordNet 1.5]