Learner's definition of WAIST
1 : the middle part of your body between the hips and chest or upper back that is usually narrower than the areas above and below it
He has a narrow waist and broad shoulders.
He put his arm around her waist.
They lay in the sun naked from the waist up. = They lay in the sun stripped to the waist.
paralyzed from the waist down = paralyzed below the waist
2 : the part of a piece of clothing that fits around your waist
— usually used in combination