maiden aunt

From King Dictionary of Contemporary English
Related topics: Family
maiden auntˌmaiden ˈaunt noun [countable] old-fashioned SSFan aunt who has never married
Examples from the Corpus
maiden auntWhen he was eighteen months old, the family broke up, his care passing to a maiden aunt.Your aupair may be a born maiden aunt.The man of letters and the maiden aunt.The maiden aunt who was invited to Walsingham House arrived in a four-wheeler.