Yes, dimes is a Scrabble word!

Verb

1. Switch (a car's headlights) from a higher to a lower beam

2. Become dim or lusterless

3. Make dim or lusterless

4. Make dim by comparison or conceal

5. Become vague or indistinct

Noun

1. A United States coin worth one tenth of a dollar

2. Street name for a packet of illegal drugs that is sold for ten dollars