The state of being topless, the state of not covering one's torso with garments. (noun)
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Use "toplessness" in a sentence
"It might take a little time to get used to but female toplessness is a part of western culture that could and should be changed."
"It had a lot of the expected Cirque acrobatics, plus a great deal of (female) toplessness."
"The double all-terrain sports stroller that the husband brought home yesterday so that the wee ones and I could travel further than three blocks together is missing the infant insert (you know, for inserting infant) and so we are trapped, TRAPPED I TELL YOU, in a miserable vortex of snot and exhaustion and toplessness – all of us – a spiralling vortex of headachey badness that will not stop until the husband comes home."