'reallocatable' originates from English, specifically the verb 'reallocate' with the adjectival suffix '-able', where the prefix 're-' comes from Latin meaning 'again' and 'allocate' comes from Latin 'allocare' (ad- 'to' + locare 'to place').

'allocate' developed from Latin 'allocare' into Old French forms (e.g. 'alouer'/'allouer') and then into Middle English; in modern English 'allocate' was combined with the prefix 're-' to form 'reallocate', and the suffix '-able' was added to create 'reallocatable'.

Initially the components literally meant 'to place again'; over time the formed adjective came to mean more generally 'able to be reassigned or redistributed' in administrative and technical contexts.