'auntish' originates from English, specifically formed by combining the noun 'aunt' with the adjectival suffix '-ish' (Old English '-isc', meaning 'having the nature of'). 'Aunt' itself comes ultimately from Latin 'amita' via Old French 'ante'/'aunte'.

'aunt' changed from Old French 'ante' (and Middle English 'aunte') derived from Latin 'amita' ('father's sister'), and the suffix '-ish' comes from Old English '-isc' (from Proto-Germanic). These elements combined in Modern English to form 'auntish'.

Initially it meant 'of or relating to an aunt' (simply aunt-like), but over time it developed the additional connotations 'having qualities associated with an aunt' such as being protective, indulgent, officious, or matronly.