We found 7 dictionaries that define the word nacreous clouds:

General (3 matching dictionaries)

1. nacreous clouds: Merriam-Webster
2. nacreous clouds: Wiktionary
3. Nacreous clouds: Wikipedia, the Free Encyclopedia

Computing (1 matching dictionary)

4. nacreous clouds: Encyclopedia

Science (1 matching dictionary)

5. Atmospheric Chemistry and Air Quality (No longer online)

Tech (2 matching dictionaries)

6. Glossary of Meteorology (No longer online)
7. National Weather Service Glossary (No longer online)

(Note: See nacreous_cloud as well.)

Definitions from Wiktionary (nacreous cloud) ▸ noun:  polar stratospheric cloud ▸ Also see nacreous_cloud ▸ Words similar to nacreous clouds ▸ Usage examples for nacreous clouds ▸ Idioms related to nacreous clouds ▸ Wikipedia articles (New!) ▸ Words that often appear near nacreous clouds ▸ Rhymes of nacreous clouds ▸ Invented words related to nacreous clouds