Def IV was an American hip hop group from Houston, Texas. The group consisted of Prince-E-Z-Cee, Vicious Lee, Jon B, and Lonnie Mac. Def IV was among the first signees to Rap-A-Lot Records, and released their only album, Nice and Hard, in 1988. Three years later, they independently released the single "D.S.L.'s", which was said to be from their upcoming album Ways of the Rhythm, but it was never released.