We found 6 dictionaries that define the word fir trees:

General (5 matching dictionaries)

1. fir trees: Collins English Dictionary
2. fir trees: Vocabulary.com
3. fir-trees: Wordnik
4. fir trees: Cambridge Advanced Learner's Dictionary
5. fir trees: TheFreeDictionary.com

Computing (1 matching dictionary)

6. fir trees: Encyclopedia

(Note: See fir_tree as well.)

Definitions from WordNet (fir tree) ▸ noun:  any of various evergreen trees of the genus Abies; chiefly of upland areas ▸ Also see fir_tree ▸ Words similar to fir trees ▸ Usage examples for fir trees ▸ Idioms related to fir trees ▸ Wikipedia articles (New!) ▸ Words that often appear near fir trees ▸ Rhymes of fir trees ▸ Invented words related to fir trees