One who is actually hot and doesn't wear undergarments and shows this in an unsluttish way, and protects her assets in the process.
Really hot girls: the ones who's breasts look nice, supported, plump, & perky in tank/sexy top, no droopy saggy. Also who wear tights/sexy pants skirts ,etc. that show enough while revealing a nice tight ass, no flat, saggy, droopy.
any female who unwisely attracts attention to what one thinks she has, yet doesn't. An attractively appealing female would have every right to show off in a similar way what one does have.
An extremely fat or scrawny female who wears tight lycra to show off is a slut.