1. Characterized by effort to the point of exhaustion; especially physical effort
   "a grueling campaign"
   - arduous, backbreaking, gruelling [Brit, Cdn], hard, heavy, laborious, operose, punishing, toilsome

See also: effortful

• pride oneself
• pride-of-India
• prideful
• pridefulness
• prie-dieu
• prier
• priest
• priest-doctor
• priest-penitent privilege
• priestcraft
• priestess
• priesthood
• Priestley
• priestlike
• priestliness
• priestly
• prig
• priggery
• priggish
• priggishly
• priggishness
• Prilosec
• prim
• prim out
• prim up