• Noun: that which has mass and occupies space; example: "an atom is the smallest indivisible unit of matter"
• Noun: a vaguely specified concern; examples: "several matters to attend to", "it is none of your affair", "things are going well"
• Noun: some situation or event that is thought about; examples: "he kept drifting off the topic", "he had been thinking about the subject for several years", "it is a matter for the police"
• Noun: a problem; example: "is anything the matter?"
• Noun: (used with negation) having consequence; example: "they were friends and it was no matter who won the games"
• Noun: written works (especially in books or magazines); example: "he always took some reading matter with him on the plane"
• Verb: have weight; have import, carry weight; example: "It does not matter much"
Nowadays love is a matter of chance, matrimony a matter of money and divorce a matter of course.
It doesn't matter who gets what. It's just a matter of doing what it takes to win.
Age is an issue of mind over matter. If you don't mind, it doesn't matter.