Definitions:

1. The measurement or apperarance of the waist, often related to fitness or clothing fit. NOUN
   • The dress has a high waistline that flatters her figure.
2. The narrowing of the body between the ribs and hips. NOUN
   • He loosened his belt around his waistline after an indulgent meal.
3. The part of the body or garment around the waist, typically the narrowest part of the torso. NOUN
   • She exercises regularly to maintain a slim waistline.

Synonyms:

• beltline
• midline
• torso
• waist