Lewis & Short

năpaeus, a, um, adj., = ναπαῖος,

  1. I. of or belonging to a wooded vale or dell: nymphae napaeae, dell-nymphs, Col. poët. 10, 264.
    Hence,
  2. II. Subst.: Năpaeae, ārum, f., the dell-nymphs: faciles venerare Napaeas, Verg. G. 4, 535; Stat. Th. 4, 255; Nemes. Ecl. 2, 20.