Literally 'butt habit'; a crude or slangy term. Can refer to fecal incontinence or, by extension, to sexual promiscuity (especially of women). The promiscuity sense is vulgar and derogatory.
I hear that person has loose sexual morals.
Due to old age, they developed incontinence and now need diapers.
Compound of 尻 (buttocks) and 癖 (habit). The exact historical derivation is uncertain; the term likely originated as a vulgar metaphor.