Yes, truer is a Scrabble word!

Adjective

1. Consistent with fact or reality; not false

2. Accurately placed or thrown

3. Devoted (sometimes fanatically) to a cause or concept or truth

4. Expressing or given to expressing the truth

5. Conforming to definitive criteria

6. Worthy of being depended on

7. Not pretended; sincerely felt or expressed

8. Rightly so called

9. Determined with reference to the earth's axis rather than the magnetic poles

10. Having a legally established claim

11. In tune; accurate in pitch

12. Accurately fitted; level