Fact

A fact is a statement that is real or true, or a thing that can be shown to be real or true. That is its core meaning, though the word has a long history, and has been used in many ways.^[1]

A fact is something that has really happened or is actually the case. The usual test for a statement of fact is whether it can be shown to be true. Standard reference works are often used to check facts. Scientific facts are verified by careful observation or measurement (by experiments or other means).

1. ↑ Shorter OED, p667.