We found 2 dictionaries that define the word diffuse nebulas:

General (1 matching dictionary)

1. diffuse nebulas: Merriam-Webster

Computing (1 matching dictionary)

2. Diffuse nebulas: Encyclopedia

(Note: See diffuse_nebula as well.)

Definitions from WordNet (diffuse nebula) ▸ noun:  a cluster of stars within an intricate cloud of gas and dust ▸ Also see diffuse_nebula ▸ Words similar to diffuse nebulas ▸ Usage examples for diffuse nebulas ▸ Idioms related to diffuse nebulas ▸ Wikipedia articles (New!) ▸ Words that often appear near diffuse nebulas ▸ Rhymes of diffuse nebulas ▸ Invented words related to diffuse nebulas