n. (Zool.) A singular marine fish of the genus Pterois, family Scorpænidæ, of several species, inhabiting the Indo-Pacific region. They are usually red, and have very large spinose pectoral and dorsal fins. [ 1913 Webster ]

n. [ Fire + Prov. E. flaire a ray. ] (Zool.) A European sting ray of the genus Trygon (T. pastinaca); -- called also fireflare and fiery flaw. [ 1913 Webster ]

n. (Zool.) The European band fish (Cepola rubescens). [ 1913 Webster ]

n.; pl. Fireflies (Zool.) Any luminous winged insect, esp. luminous beetles of the family Lampyridæ. [ 1913 Webster ]

☞ The common American species belong to the genera Photinus (especially Photinus pyralis) and Photuris, in which both sexes are winged. The name is also applied to luminous species of Elateridæ. See Fire beetle. [ 1913 Webster +PJC ]

n. (Biochem.) a type of luciferin produced by the firefly Photinus pyralis. Its structure has been elucidated, and chemically it is recognized as 4, 5-Dihydro-2-(6-hydroxy-2-benzothiazol-2-yl)-4-thiazolecarboxylic acid, C11H8N3O2S2. It has found use in a very sensitive assay for ATP, in which concentrations of ATP as low as 10-11 molar can be detected. [ MI11 ] [ PJC ]