'inclusive' originates from Latin, specifically the word 'inclusivus', ultimately from 'includere', where 'in-' meant 'in' and 'cludere/claudere' meant 'to shut or close'.

'inclusive' changed from Latin 'includere' (to shut in) > past participle/form 'inclusus' > Late Latin/Medieval Latin 'inclusivus' > via Old French/Modern French forms (e.g. 'inclusif') into modern English 'inclusive'.

Initially it meant 'shut in' or 'enclosed', but over time it evolved to mean 'containing or including' and, by extension, 'not excluding (people)'.