IPA: /ˈbʌt.ək/
KK: /ˈbʌtək/
One of the two rounded parts at the back of the human body, located below the waist and formed by muscles and fat.
He fell and landed hard on his buttock.
Buttock originates from Old English 'buttuc', meaning the back part or the rear. The word refers specifically to the rounded part of the body at the back.
Think of the Old English 'buttuc' which refers to the back part — this helps you remember that 'buttock' refers to the rounded part at the back of the body.