It is unimportant that; it doesn't (didn't) matter that.

The quality of being matterful.

(astronomy, astrophysics) Particles of matter that cannot be detected by their radiation but whose presence is inferred from gravitational effects.

The matter or thought presented for consideration in some statement or discussion; that which is made the object of thought or study.

Alternative spelling of fecal matter

(idiomatic) Brains; a person's ability to think. / Literal brains as a general substance. / (neuroanatomy) A collection of cell bodies and (usually) dendritic connections, in contrast to white matter.

(idiomatic) What is wrong? What's the problem? / (dated) What's happening? What's the news?

a fact / (idiomatic) a more factual correction / (idiomatic) something completely true

(American spelling) Alternative spelling of grey matter

A fact or statement that is recorded in governmental records or in publications. / (law) A fact that is contained within court files or has otherwise been entered into evidence before the court.