means The physical stuff that things are made of — anything with mass that takes up space — or, as a verb, to be of importance.

from From Latin 'materia,' meaning building material or timber, which itself grew from 'mater,' mother — the idea being the source-stuff from which things are made. It reached English through Old French 'matiere.' The 'to be important' sense is a later branch: if something is 'a matter,' it's a thing of substance worth attending to.