"glowing with heat, rendered luminous by heat," 1794, from French incandescent (18c.) or directly from Latin incandescentem (nominative incandescens), present participle of incandescere "become warm, glow, kindle," from in- "within" (from PIE root *en "in") + candescere "begin to glow, become white," inceptive of candere "to glow, to shine" (from PIE root *kand- "to shine"). In reference to electric light, from 1881. The verb incandesce (1838), originally in science, is perhaps a back-formation.
1650s, figurative, "state of being 'inflamed,' " from French incandescence, from incandescent (see incandescent). Literal meaning "the condition of glowing from heat" is by 1794.
It forms all or part of: candela; candelabrum; candescent; candid; candidate; candle; candor; chandelier; chandler; frankincense; incandescence; incandescent; incendiary; incense (n.) "substance producing a sweet smell when burned;" incense (v.1) "to provoke, anger."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit cand- "to give light, shine," candra- "shining, glowing, moon;" Greek kandaros "coal;" Latin candere "to shine;" Welsh cann "white," Middle Irish condud "fuel."
1713, "what sparkles" (often of gems, wits, or women), agent noun from sparkle (v.). In the modern hand-held fireworks sense, from 1905.
The New York Board of Fire Underwriters has issued a warning against the storage, sale and use of a new form of fireworks now on the market. These are known as "electric sparklers," are made in Germany, and come to this country in metal lined cases each containing 120 dozen of pasteboard boxes with 12 sparklers in each box. The Board's warning says that while the sparklers appear harmless, the solid incandescent mass is intensely hot and readily communicates fire to any inflammable substance it may touch. [The Standard (weekly insurance newspaper), Boston, May 4, 1907]