Yes, used is a Scrabble word!

Adjective

1. Employed in accomplishing something

2. Of persons; taken advantage of

3. Previously used or owned by another

Verb

1. Put into service; make work or employ for a particular purpose or for its inherent or natural purpose

2. Take or consume (regularly or habitually)

3. Use up, consume fully

4. Seek or achieve an end by using to one's advantage

5. Avail oneself to

6. Habitually do something (use only in the past tense)