'aunthood' originates from Modern English, specifically formed from the word 'aunt' and the suffix '-hood', where 'aunt' meant 'the sister of one's parent' and '-hood' meant 'state' or 'condition' (the suffix ultimately from Old English 'hād').

'aunthood' developed as a compound from Middle English elements: the noun 'aunt' (from Old French/Middle English forms such as 'ante'/'aunte', ultimately from Latin 'amita') combined with the Old English suffix 'hād' (which became Middle English '-hood'), and eventually became the modern English formation 'aunthood'.

Initially, it meant 'the condition or state of being an aunt', and this basic meaning has remained stable into modern usage.