\Mer"maid\, n. [AS. mere lake, sea. See {Mere} lake, and
{maid}.]
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} (Zo["o]l.) the angel fish ({Squatina}).
{Mermaid's glove} (Zo["o]l.), a British branched sponge
   somewhat resembling a glove.
{Mermaid's head} (Zo["o]l.), 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 {P.
   pectinacea}).