A fabled marine creature, typically represented as having the upper part like that of a woman, and the lower like a fish; a sea nymph, sea woman, or woman fish.
Chaucer uses this word as equivalent to the siren of the ancients. Mermaid fish, a European spatangoid sea urchin (Echinocardium cordatum) having some resemblance to a skull.
(Science: botany) Mermaid weed, an aquatic herb with dentate or pectinate leaves (Proserpinaca palustris and P. Pectinacea).
Origin: AS. Mere lake, sea. See Mere lake, and maid.