We found 6 dictionaries that define the word know for a fact:

General (4 matching dictionaries)

1. know for a fact: Merriam-Webster
2. know for a fact: TheFreeDictionary.com

Business (1 matching dictionary)

3. know for a fact: Legal dictionary

Miscellaneous (1 matching dictionary)

4. know for a fact: Idioms

▸ Words similar to know for a fact ▸ Usage examples for know for a fact ▸ Idioms related to know for a fact ▸ Wikipedia articles (New!) ▸ Words that often appear near know for a fact ▸ Rhymes of know for a fact ▸ Invented words related to know for a fact