'old-womanish' is formed from the English words 'old' + 'woman' with the suffix '-ish' (from Old English '-isc'), where '-ish' meant 'having the nature of' or 'related to'.

'old' comes from Old English 'eald'; 'woman' derives from Old English 'wīfmann' (later Middle English 'womman'/'woman'); the adjectival suffix '-ish' comes from Old English '-isc' and developed into Modern English '-ish'. The compound 'old-woman-ish' follows the pattern of English compounding to mean 'having qualities of an old woman'.

Originally a straightforward compound meaning 'having the qualities of an old woman', its use became commonly pejorative over time, implying fussiness, prudishness, or dowdiness rather than merely age-related qualities.