a. 1. Having no top, or no visble fop; hence, fig.: very lofty; supreme; unequaled. “ The topless Apennines.” “Topless fortunes.” Beau. & Fl. [ 1913 Webster ]
2. wearing no clothes above the waist, said especially of women. [ PJC ]
3. featuring entertainment by women wearing no clothes above the waist; as, a topless go-go joint. [ PJC ]