Green’s Dictionary of Slang

second-rate, weak, inadequate.

1999		M.D. Metz Outsider 3: You’re not going to spend your life in a town that has [...] one lame-o comedy club, one even more lame-o dance club.
2006		J. Henneman Always Listen to the Ravings of a Mad Woman 27: ‘I’m not listening to this.’ ‘Fine, but not the lame-o crap you listen to, either.’ ‘It is not lame-o. It’s...retro.’.
2017		S.M. Jones August Snow [ebook] I drank the lame-o decaf.