What does a "truly intelligent" person even mean? Intelligence doesn't have an objective actual definition that is reliable and not contradictory. It is so odd

What does a "truly intelligent" person even mean? Intelligence doesn't have an objective actual definition that is reliable and not contradictory. It is so odd, that in science, you wouldn't make tests for something you haven't defined, but for some reason everyone believes to have an objective, reliable and consistent definition of intelligence. People just rush to come up with tests for some reason. It is really odd