\Ler*ne"an\ (l[~e]r*n[=e]"an), n. [See {Lern[ae]a}.] (Zo["o]l.) One of a family ({Lern[ae]id[ae]}) of parasitic Crustacea found attached to fishes and other marine animals. Some species penetrate the skin and flesh with the elongated head, and feed on the viscera. See Illust. in Appendix.