We found 11 dictionaries that define the word effs:

General (7 matching dictionaries)

1. effs: Merriam-Webster
2. effs: Collins English Dictionary
3. effs: Vocabulary.com
4. effs: Cambridge Advanced Learner's Dictionary
5. effs: Wiktionary
6. EFFS: Dictionary.com
7. EFFS: TheFreeDictionary.com

Computing (1 matching dictionary)

8. EFFS: Encyclopedia

Medicine (1 matching dictionary)

9. EFFS: Medical dictionary

Miscellaneous (1 matching dictionary)

10. EFFS: Acronym Finder

Slang (1 matching dictionary)

11. Effs: Urban Dictionary

(Note: See eff as well.)

Definitions from Wiktionary (Effs) ▸ noun:  Alternative letter-case form of effs Phrases: effs and blind, more... ▸ Words similar to effs ▸ Usage examples for effs ▸ Idioms related to effs ▸ Wikipedia articles (New!) ▸ Popular adjectives describing effs ▸ Words that often appear near effs ▸ Rhymes of effs ▸ Invented words related to effs