‖n. pl. [ NL., from Gr. &unr_;, a nettle. ] A group of Cœlenterata, including the Medusæ or jellyfishes, and hydroids; -- so called from the stinging power they possess. Sometimes called sea nettles. [ 1913 Webster ]

{ n.; pl. Acalephs Acalephans [ See Acalephæ. ] (Zool.) One of the Acalephæ. [ 1913 Webster ]

a. [ Acaleph + -oid. ] (Zool.) Belonging to or resembling the Acalephæ or jellyfishes. [ 1913 Webster ]