Incandescent means glowing white-hot. A filament in an old light bulb, metal in a forge.
The literal sense is physics: an incandescent bulb makes light by heating a wire until it glows, which is why the old bulbs ran so hot and why they lost to LEDs. The figurative sense is the one you will meet in a newspaper, and it means blazingly angry — the minister was incandescent, he was incandescent with rage. That leap from heat to temper is one English makes often, alongside burning, seething and fuming. A third and gentler use means brilliant: an incandescent performance.
1adjectiveincandescentGlowing with intense heat.
“The furnace door opened on an incandescent glow.”
2adjectivefuriousExtremely angry.
“She was incandescent when she read the letter.”
Incandescent is going white. Latin candidus meant white and incandēscere to grow hot and glow, so the lamp and the temper are both described by their colour.
Latin
incandescens
French
incandescent
English, today
incandescent
Built from
French incandescent, from Latin incandescens, from incandesco (“be heated, glow”), from in- + candesco, from candidus (“white”).
Etymology from Wiktionary, CC BY-SA