Pierides — and sometimes also in the singular, Pieris, a surname of the Muses, which they derived from…
Ancient Greek word, found 15 times in the texts on Socratos.
Theocritus, Εἰδύλλια 10.24: Μοῖσαι Πιερίδες, συναείσατε τὰν ῥαδινάν μοι