From Longman Dictionary of Contemporary Englishold girlˈold girl noun [countable] British English 1 SESa woman who is a former student of a school an old girls’ reunion2 spokenOLD/NOT YOUNG an old woman She’s a nice old girl! → old boy
Examples from the Corpus
old girl• The old man went into one wing of the workhouse and the old girl went to the other.• The old girl should do her duty and send me a postcard if she can take the time off from her toy-boys. 