Yes, mated is a Scrabble word!

Adjective

1. Mated sexually

2. Used of gloves, socks, etc.

3. Of or relating to a marriage partner

Verb

1. Engage in sexual intercourse

2. Bring two objects, ideas, or people together

3. Place an opponent's king under an attack from which it cannot escape and thus ending the game

4. Twist together or entwine into a confusing mass

5. Change texture so as to become matted and felt-like