matter of fact is a noun meaning "a disputed factual contention that is generally left for a jury to decide". It carries 2 recorded senses.
a disputed factual contention that is generally left for a jury to decide
a matter that is an actual fact or is demonstrable as a fact
Definitions, synonyms and semantic relations for matter of fact come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.