coolio adjective fashionable; acceptable US An elaboration of COOL; probably also a reference to rapper Coolio who enjoyed a huge international success in the mid-1990s.
— Connie Eble (Editor), UNC-CHCampusSlang, p. 2, April 1997
It’s not supposed to be Coolio to be early all the time, but it does always seem to work out that I’m the first one there. — Kevin Sampson, Outlaws, p. 3, 2001