(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.

simple past tense and past participle of mat

forming a thick tangled mess / covered with mats or matting