We found 17 dictionaries that define the word fatter:

General (12 matching dictionaries)

1. fatter: Merriam-Webster
2. fatter: Oxford Learner's Dictionaries
3. fatter: Collins English Dictionary
4. fatter: Vocabulary.com
5. Fatter, fatter: Wordnik
6. fatter: Cambridge Advanced Learner's Dictionary
7. fatter: Wiktionary
8. Fatter, fatter: Dictionary.com
9. fatter: Cambridge Essential American English Dictionary
10. Fatter: Wikipedia, the Free Encyclopedia
11. fatter: FreeDictionary.org
12. fatter: TheFreeDictionary.com

Computing (1 matching dictionary)

13. fatter: Encyclopedia

Medicine (2 matching dictionaries)

14. fatter: Merriam-Webster Medical Dictionary
15. fatter: Medical dictionary

Miscellaneous (1 matching dictionary)

16. fatter: Idioms

Slang (1 matching dictionary)

17. Fatter: Urban Dictionary

(Note: See fat as well.)

Definitions from Wikipedia (Fatter) ▸ noun:  an Iranian short-range air-to-air missile based on the U.S.-built AIM-9 Sidewinder missile. Types: lard, tallow, suet, bacon grease, schmaltz, ghee, more... Phrases: bigger fatter, more... ▸ Words similar to fatter ▸ Usage examples for fatter ▸ Idioms related to fatter ▸ Wikipedia articles (New!) ▸ Popular adjectives describing fatter ▸ Words that often appear near fatter ▸ Rhymes of fatter ▸ Invented words related to fatter