'reclusion' originates from Latin, specifically the word 'reclusio', where 're-' meant 'back' or 'away' and 'cludere/claudere' (in the related root) meant 'to shut'.

'reclusion' changed from Old French 'reclusion' and Middle English 'reclusioun' and eventually became the modern English word 'reclusion'.

Initially, it meant 'a shutting up' or 'confinement', but over time it evolved into its current sense of 'withdrawal from society; living apart'.