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

See also: effortful, operoseness

• round scad
• round shape
• round shot
• round steak
• round the bend
• round the clock
• round top
• round trip
• round whitefish
• round window
• round-arm
• round-backed
• round-bottom
• round-bottom flask
• round-bottomed
• round-eyed
• round-faced
• round-fruited
• round-headed leek
• round-leaved rein orchid
• round-shouldered
• round-spored gyromitra
• round-table conference
• round-tailed muskrat
• round-the-clock patrol