Unable to control bodily functions like urination or defecation; also historically means lacking self-control or moral restraint.
From Latin incontinens 'unable to hold' (in- 'not' + continens 'holding together'). Originally a word about self-control before becoming medical.
This word used to be a general insult about someone being morally loose or undisciplined before medicine started using it for a specific bodily condition. It's a good example of how the same word can slide from being an attitude criticism to a neutral medical term.
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