waistline
n. countable B1 Intermediate US //ˈweɪstˌɫaɪn// UK //wˈeɪslaɪn// waist·line
n. the part of your body between your ribs and your hips. It is often used when talking about clothes that fit around this area or how much someone weighs.
n. the part of the human body between the ribs and the hips. Often used in the context of clothing fit or body weight management.
She bought a new dress that fits perfectly around her waistline.
After a long day of hiking, he noticed his waistline was a bit tighter than usual from all the snacks he had eaten.
From waist + line.