We found 4 dictionaries that define the word flat four:

General (3 matching dictionaries)

1. flat-four: Oxford Learner's Dictionaries
2. flat-four: Wordnik
3. Flat-four, Flat four: Wikipedia, the Free Encyclopedia

Tech (1 matching dictionary)

4. AUTOMOTIVE TERMS (No longer online)

Phrases: flat back four, more... ▸ Words similar to flat four ▸ Usage examples for flat four ▸ Idioms related to flat four ▸ Wikipedia articles (New!) ▸ Words that often appear near flat four ▸ Rhymes of flat four ▸ Invented words related to flat four