'nonreallocatable' originates from Modern English, formed from the negative prefix 'non-' and the adjective 'reallocatable', where 'non-' meant 'not', 're-' meant 'again', and 'allocatable' comes from 'allocate' meaning 'to place or assign'.

'nonreallocatable' changed from the phrase 'not reallocatable' and from the formed compound 'non-' + 'reallocatable' into the single modern adjective 'nonreallocatable'. 'Reallocatable' itself comes from 're-' + 'allocatable'; 'allocatable' derives from the verb 'allocate', which traces back to Latin 'allocare' via Medieval/Modern Latin and Old French.

Initially, the components conveyed 'not' + 'again' + 'to place'; over time the compound became a technical term meaning specifically 'cannot be reassigned or resized' (commonly in computing or finance contexts).