Yes, caller is a Scrabble word!

Adjective

1. Providing coolness

2. Fresh

Noun

1. A social or business visitor

2. An investor who buys a call option

3. The bettor in a card game who matches the bet and calls for a show of hands

4. A person who announces the changes of steps during a dance

5. Someone who proclaims or summons in a loud voice

6. The person who convenes a meeting

7. The person initiating a telephone call