IPA: /ˈbɒdiˌbɪldɪŋ/
KK: /ˈbɑdiˌbɪldɪŋ/
The activity of improving the body's muscles and shape through exercise and diet, often for competitions.
He spends several hours a week on bodybuilding to prepare for the competition.
Bodybuilding is formed from "body" (from Old English "bodig", meaning the physical structure of a person or animal) and "building" (from Old English "bylding", meaning the act of constructing or forming). The word refers to the act of constructing or developing the physical structure of the body, particularly through exercise and nutrition.
Think of 'body' as the physical structure and 'building' as the act of constructing — bodybuilding is all about constructing and developing your physical body.