Molly dancer
/ˈmɒli ˌdɑːnsə/ /ˈmɒli ˌdansə/English regional (especially northern )
noun
A person who participates in a traditional English dance or masquerade; (more generally) a morris dancer.
Origin
Late 19th century; earliest use found in Advertiser (Stockport) Notes & Queries. Probably from Molly, pet-form of the female forename Mary + dancer: see quot. 1959.