'bagne' originates from French, specifically the word 'bagne', which in French denoted a prison for forced labor or a penal colony.

'bagne' ultimately derives from Italian 'bagno' (meaning 'bath'), which comes from Latin 'balneum' ('bath'). The Italian 'bagno' was used in late medieval/early modern contexts to refer to galleys or prison hulks where convicts were confined; French borrowed this sense as 'bagne' and English later borrowed the French term.

Initially related to 'bath' (from Latin 'balneum'), the sense shifted in Italian and French to refer to places of confinement (galleys, prisons), and in modern English it denotes a penal colony or harsh prison system.