dark
The suffix for the word luminous is "-ous."
The opposite of luminous is "non-luminous" or "dark." While luminous objects emit or reflect light, non-luminous objects do not produce their own light and may appear dark or shadowy. In a broader sense, terms like "dull" or "dim" can also convey a lack of brightness or illumination.
The word "luminous" can be found in "The Giver" in the following sentence: "Jonas blinked at the luminous sun."
We could see the deep craters on the luminous moon.
Some words with "lumin" as a root word include illuminate, luminous, and bioluminescent.
Luminous worms hung in caves and spun light silk.
The cat's luminous green eyes shone in the dark night.
bright
My father had a luminous watch, so in the middle of the night he could tell what time it was.
luminous
The L Word - 2004 Luminous 2-7 is rated/received certificates of: USA:TV-MA
The summer night was not dark, but filled with the luminous presence of fireflies and the golden full moon.