Yes, rebel is a Scrabble word!

Verb

1. Take part in a rebellion; renounce a former allegiance

2. Break with established customs

Noun

1. `Johnny' was applied as a nickname for Confederate soldiers by the Federal soldiers in the American Civil War; `greyback' derived from their grey Confederate uniforms

2. A person who takes part in an armed rebellion against the constituted authority (especially in the hope of improving conditions)

3. Someone who exhibits great independence in thought and action