the narrow part in the middle of the human body:
The skirt was too big around the waist.
from the waist up/down (=in the top or bottom half of your body)
Lota was paralysed from the waist down.
stripped to the waist (=not wearing any clothes on the top half of your body)
slim-waisted/narrow-waisted/thick-waisted (=having a thin, thick etc waist)
2DCC [usually singular]
the part of a piece of clothing that goes around this part of your body
! Do not confuse with waste (used as a verb and noun to talk about using too much of something for unimportant or unnecessary things).