We found 4 dictionaries that define the word four f's:

General (2 matching dictionaries)

1. four F's: Wiktionary
2. Four Fs (evolution), Four Fs: Wikipedia, the Free Encyclopedia

Medicine (1 matching dictionary)

3. Four Fs (disambiguation), Four f's, four Fs: Medical dictionary

Slang (1 matching dictionary)

4. four f's, the four F's: Urban Dictionary

Definitions from Wiktionary (four F's) ▸ noun:  A set of four basic biological instincts: feeding, fighting, fleeing, and fucking. ▸ Words similar to four f's ▸ Usage examples for four f's ▸ Idioms related to four f's ▸ Wikipedia articles (New!) ▸ Words that often appear near four f's ▸ Rhymes of four f's ▸ Invented words related to four f's