1. Consistent with fact or reality; not false
2. Reliable as a basis for action
3. Having a legally established claim; SYN. lawful, rightful.
4. Rightly so called
5. Devoted (sometimes fanatically) to a cause or concept of truth
6. Accurately placed or thrown; SYN. dead on target.
7. Accurately fitted; level; SYN. straight.
8. Determined with reference to the earth's axis rather than the magnetic poles
9. (Biology) Conforming to the definitive criteria of a natural group