From Longman Dictionary of Contemporary Englishbe no mean performer/player etcbe no mean performer/player etcGOOD/EXCELLENTto be very good at doing something Kinnock is no mean performer on the rugby field. → mean
Examples from the Corpus
be no mean performer/player etc• Kinnock fils, who is no mean performer on the rugby field, has developed a taste for academe. 