1. The physical substance in general, as distinct from mind and spirit; (in physics) that which occupies space and possesses rest mass, especially as distinct from energy.
2. A subject or situation under consideration.
3. The reasons for distress or a problem.
4. Be important or significant.
Plural noun: Matters.
Verb forms: Matter, Mattered, Mattered.
1. It does not matter in which car he is going to come.
2. What is the matter now?
3. The structure and properties of matter.