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

See also: effortful

• tournedos
• tourney
• tourniquet
• Tours
• tourtiere
• tousle
• tousled
• tout
• tout de suite
• tout ensemble
• touter
• tovarich
• tovarisch
• tovarish
• tow
• tow car
• tow truck
• tow-headed snake
• seed fern
• seed grain
• seed lac
• seed leaf
• seed money
• seed oyster
• seed pearl