What is the noun form of the word 'Luminous'?

• The noun form of the word 'Luminous' is - Luminosity

Luminous (adjective)
English Meaning: Softly bright or radiant.
Bangla Meaning:
(১) আলোকোজ্জ্বল; উজ্জ্বল: luminous paint.
(২) (লাক্ষণিক) স্পষ্ট; সহজবোধ্য।

Other Forms:
Luminosity (noun) [uncountable noun] স্পষ্টতা; সহজবোধ্যতা।
luminescent (adjective)
luminous (adjective)
luminously (adverb)

Source: Website Lecture.