The term 'more rational' can be expressed in two different ways: SANER (5 letters) and SEINER (6 letters). The word SANER is derived from the Latin word sanus, which means 'HEALTHY' or 'SOUND'. It is used to describe someone who is more reasonable and logical than others. The word SEINER is derived from the German word sein, which means 'to be'. It is used to describe someone who is more thoughtful and reflective than others. Both words imply that the person is more rational than others.