REASON

Definition

1. verb decide by reasoning. — synonyms: reason_out, conclude
2. verb present reasons and arguments. — synonyms: argue
3. verb think logically.
4. noun a rational motive for a belief or action. — synonyms: ground
5. noun an explanation of the cause of some phenomenon.
6. noun the capacity for rational thought or inference or discrimination. — synonyms: understanding, intellect
7. noun the state of having good sense and sound judgment. — synonyms: rationality, reasonableness
8. noun a justification for something existing or happening. — synonyms: cause, grounds
9. noun a fact that logically justifies some premise or conclusion.