FIREFLY

firefly, lightning bug

(noun) nocturnal beetle common in warm regions having luminescent abdominal organs

firefly, fire beetle, Pyrophorus noctiluca

(noun) tropical American click beetle having bright luminous spots

Source: WordNet® 3.1

Etymology

Noun

firefly (plural fireflies)

Any beetle of the family Lampyridae, which exhibit bioluminescence during twilight.

Synonyms

• (beetle): lightning bug

Source: Wiktionary

Fire"fly`, n.; pl. Fireflies (. (Zoöl.)

Definition: Any luminous winged insect, esp. luminous beetles of the family Lampyridæ.

Note: The common American species belong to the genera Photinus and Photuris, in which both sexes are winged. The name is also applied to luminous species of Elateridæ. See Fire beetle.

Source: Webster’s Unabridged Dictionary 1913 Edition