batwing sleeve

adjective

1. formed, shaped, etc., like the wing of a bat.
2. (of a garment or part of a garment) resembling or conceived of as resembling the wing of a bat, as a loose long sleeve (batwing sleeve) having a deep armhole and a tight wrist.

noun

1. a sleeve of a garment with a deep armhole and a tight wrist

adjective

1. shaped like the wings of a bat, as a black tie, collar, etc