lumination
Illumination; specifically, artificial illumination.
countable, rare, uncountable
The most delicate test for phosphorus is the distillation of the suspected substance, especially flour paste, with a little sulphuric acid and water. […] Where the aqueous vapors from the flask reach the cooling tube, a lumination is constantly observed in the dark, usually a luminous ring. […] If ether, alcohol or turpentine are present, they will prevent the lumination, which commences as soon as they have passed over.
Where it comes from
From luminate + -ion, or a Latin *lūminātiōnem (“illumination”), from lūminō (“to brighten, to illuminate; to reveal (throw light on)”), from lūmen (“light”) (probably from lūx (“light”) + -men (suffix forming neuter nouns of the third declension)), from Proto-Indo-European *lewk-s-men (“light”) (from Proto-Italic *louks, from Proto-Indo-European *lewk- (“bright; light; white”) + *-mn̥ (suffix indicating a noun))) + Latin -tiōnem (“-tion”, suffix forming a noun relating to some action or the result of an action) (from Proto-Italic *-tiō, from Proto-Indo-European *-tis (suffix forming nouns from verbs)).
Adapted from the Wiktionary entry lumination (CC BY-SA 4.0).