A crew cut is a type of haircut in which the upright hair on the top of the head is cut relatively short, graduated in length from the longest hair that forms a short pomp (pompadour) at the front hairline to the shortest at the back of the crown so that in side profile, the outline of the top hair approaches the horizontal. Relative to the front view, and to varying degrees, the outline of the top hair can be arched or flattened at the short pomp front and rounded or flattened over the rest of the top to complement the front hairline, head shape, face shape and facial features. The hair on the sides and back of the head is usually tapered short, semi-short, or medium.
A short crew cut is sometimes referred to as a butch, though with the exception of variant forms, a butch differs from a crew cut in that the top hair is cut a uniform short length. A long crew cut can be referred to in the US as an ivy league crew cut or ivy league. A crew cut where the hair on the top of the head is graduated in length from the front hairline to a chosen point on the mid to back part of the crown as a flat plane, of level, upward sloping or downward sloping inclination is known as a flat top crew cut or flattop. Crew cuts, flattop crew cuts, butch cuts and ivy leagues can be referred to as buzz cuts; all are traditionally groomed with hair control wax, commonly referred to as butch wax.
The crew cut, regardless of the name applied to the hairstyle, was not limited to, nor did the style originate in the United States. In English, the crew cut and flat top crew cut were formerly known as the pompadour or short pompadour, as well as the brush cut, and had been worn since at least the mid 18th century. The style went by other names in other languages; in French, coupé en brosse; in German, bürstenschnitt; in Russian, ёжик. A short pompadour with a flat top was considered the standard while a somewhat curved appearance across the top was suggested for wider foreheads and face shapes. The style with a flat top acquired the name brush top short pompadour and the style with a more rounded top, round top short pompadour. Prior to the invention of electric clippers with a motor in the handle in 1921 and their ensuing marketing and widespread use, barbers considered the perfect short pompadour to be the most time consuming style to trim.