Definition

Not giving off light or brightness; dark.

Example

The nonluminous surface of the moon reflects sunlight but does not emit its own light.

Conversation

Have you ever noticed how some stars are really nonluminous?

Yeah, it's interesting how many of them we can't see clearly.

I mean, they might be there, but they're just too faint to notice.

Exactly! It's amazing how much is out there that we can't even see.

Synonyms & Antonyms

Root Explanation

Nonluminous → It is formed from "non-" (meaning not) and "luminous" (from Latin "luminis", meaning light). The word "nonluminous" describes something that does not emit or produce light.

Memory Tip

Think of 'non-' meaning 'not' and 'luminous' relating to 'light' — so nonluminous refers to something that is not light-producing.

Visually Confused Words