Yes, powder is a Scrabble word!

Verb

1. Make into a powder by breaking up or cause to become dust

2. Apply powder to

Noun

1. A solid substance in the form of tiny loose particles; a solid that has been pulverized

2. A mixture of potassium nitrate, charcoal, and sulfur in a 75:15:10 ratio which is used in gunnery, time fuses, and fireworks

3. Any of various cosmetic or medical preparations dispensed in the form of a pulverized powder