A-line

Short definition from Wiktionary

Adjective

1. 1
   Having a silhouette that replicates the letter A by flaring out from the top, like a funnel, narrow and fitted at the neck and shoulders, skimming the hips and widening toward the bottom, with little or no shaping or seaming at the waist.

Noun

1. 1
   Any article of clothing with a narrow mid-section and a flared bottom.