waistline

Etymology

From waist + line.

noun

1. a line around the body at the waist; its measurement
2. the narrowest part of a garment, usually at the waist, but may be above or below depending on the dictates of fashion or the whim of the designer
3. (slang) person having a large waistline
4. The horizontal line just below the windows of a car or other vehicle.
   … with the adoption of a curved bodyside profile Bulleid considerably raised the height of the waistline and at the shoulder height of seated passengers, just where the extra space was most needed. 1979 August, Graham Burtenshaw, Michael S. Welch, “O.V.S. Bulleid's SR loco-hauled coaches - 1”, in Railway World, page 396