The drape, or the hand of a fabric describes the way it will hang, its reaction to gravity and how it falls, and therefore its suitability for purpose.
A stiff, uncompromising fabric will have poor drape and will hang awkwardly. If a fabric drapes well in the hand, you’ll know it has the ability–enough weight and fluidity–to hang into pleasing folds without creasing, flattening or springing back.