'reassign' originates from Latin-derived elements: the prefix 're-' (from Latin, meaning 'again') combined with 'assign' (from Latin 'assignare'), where 'ad-' meant 'to/toward' and 'signare' meant 'to mark or sign'.

'assign' came into English via Old French 'assigner' from Latin 'assignare'; the modern English verb 'reassign' was formed by adding the productive prefix 're-' to 'assign' in later English usage to mean 'assign again'.

Initially, 'assign' meant 'to mark out or allocate'; with the addition of 're-' the compound came to mean 'to assign again or to transfer to a different role or place,' a usage that has remained stable in modern English.