We found 3 dictionaries that define the word brown coals:

General (3 matching dictionaries)

1. brown coals: Merriam-Webster
2. brown coals: Collins English Dictionary
3. brown coals: Vocabulary.com

(Note: See brown_coal as well.)

Definitions from Wiktionary (brown coal) ▸ noun:  lignite ▸ Also see brown_coal ▸ Words similar to brown coals ▸ Usage examples for brown coals ▸ Idioms related to brown coals ▸ Wikipedia articles (New!) ▸ Words that often appear near brown coals ▸ Rhymes of brown coals ▸ Invented words related to brown coals