Mer·maid n. 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.
Note: ☞ Chaucer uses this word as equivalent to the siren of the ancients.
Mermaid fish Zool. the angel fish (Squatina).
Mermaid's glove Zool., a British branched sponge somewhat resembling a glove.
Mermaid's head Zool., a European spatangoid sea urchin (Echinocardium cordatum) having some resemblance to a skull.
Mermaid weed Bot., an aquatic herb with dentate or pectinate leaves (Proserpinaca palustris and Proserpinaca pectinacea).
n : half woman and half fish; lives in the sea