<2014 “I watched it go, lost in recollection. This memory was candescent, irresistible.”—“H is for Hawk” by Helen Macdonald, page 8>
Don't recall seeing candescent without the “in” out front, as in “incandescent light bulb”.
So what does candescent mean?
OXFORD ENGLISH DICTIONARY
CANDESCENT adjective, rare: Glowing with, or as with, heat.
Etymology: From Latin candēscent-em, present participle of candēscĕre to become white, begin to glow, inchoative from candēre
<1824 “All the snows took fire and burned with a candescent brilliancy.”—Letters of T. L. Beddoes in Works (1935), page 588>
<1863 “The spark. . . cast forth from the candescent metal.”—Quarterly Review, Vol. 114, page 540>
<1884 “The star. . . less candescent than before.”—Ben-Hur by L. Wallace, i. xiv. page 68>
[[Some more recent examples from archived sources:
<1994 “‘With This Ring’ is a candescent ballad, reflecting on the commitment of marriage.”—Miami Times (Florida), 5 May>
<2002 “He felt himself drawn into a candescent and unbearable eternity; he felt he was falling into a void, pulled down by hooks sunk into his flesh.”—The Literary Review, 22 September>
<2009 “Last night, at La Vie Argentina Restaurant in the hip candescentneighborhood of Mexico City, . . .”—NPR Morning Edition, 29 April>
<2011 “. . . the United Records pressing plant in Nashville . . . churned out a special one-sided, two-colored vinyl edition that looks like a 12-inch-round piece of candescent taffy.”—Star Tribune (Minneapolis, Minnesota) 12 August>
<2012 “Martin Hanna turns in two candescent portrayals, as Ali, the blind Indian, and Ignacio, a father-ghost.”— The Pantagraph (Bloomington,Illinois), 2 October>
<2015 “Artists' stories and ideas blazed a trail of images in candescent chalk colors along three blocks of Broad Street's stark white sidewalks.”— Standard-Speaker (Hazleton, Pennsylvania), 9 August
INCANDESCENT adjective (and noun)
Etymology: From Latin incandēscent-em, present participle of incandēscĕre to incandesce, verb.: so in French (1798 in Dictionnaire Académie).
a)  Emitting light on account of being at a high temperature; glowing with heat.
b)  general: Glowing, brightly shining, brilliantly luminous.
c) transferred sense Intensely hot, rare.
d) figurative: Becoming or being warm or intense in feeling, expression, etc.; ardent, fiery; ‘flaming up’.
e) technical : Applied to that form of electric light produced by the incandescence of a filament or strip of carbon.
I’ve got a strong feeling that in practical terms, in most instances ‘candescent’ and ‘incandescent’ can be considered synonyms (see below). (Also think flammable/inflammable).
CANDESCENCE noun The state of being white hot; incandescence.
CANDESCENT adjective Glowing; incandescent
Actually, a hair-splitting difference I see between the two is that candescent is just ‘glowing’ with or without heat, whereas incandescent is glowing due to heat only.
On January 1, 2014, in keeping with a law passed by Congress in 2007, the old familiar tungsten-filament 40- and 60-watt incandescent light bulbs can no longer be manufactured in the U.S., because they don't meet federal energy-efficiency standards (75- and 100-watt bulbs were banned earlier). However, it is still legal to use them, and stores that have them in stock can still sell them. New energy-efficient bulbs (Halogen, CFL, and LED) that produce the same amount of light as the 40- and 60-watt bulbs are legal. For example, a 43-watt bulb will replace the 60-watt bulb, with a similar story for other wattages. And incandescent can still be a choice — if they can come up with a more efficient version. Some specialty bulbs such as three-way bulbs, refrigerator bulbs, and plant grow lights are exempt.
So, don’t go into a store and ask for a ‘candescent’ light bulb, because unless they read Wordwizard you’ll get a song and dance about how you're pronouncing it wrong. (<:)
Ken G – December 15, 2015
Discuss word origins and meanings.
End of topic.