mullet
Business in the front, party in the back.
A men's haircut that has waxed and waned in popularity since the 1970s. The hair is cut short at the front and sides, but left long at the back. It has at times been associated with the rock and country music genres, lesbian subculture, and professional athletes.
A mullet with a narrow lock of hair tied or braided in the back is known as a rattail.