An online dictionary defines intelligence as:

Intelligence:

The capacity to acquire and apply knowledge.
*To broad, because if that were true, machines would be intelligent. Which is not true*

The faculty of thought and reason.
*Better definition, because to reason, means that we can make choices. Choices we make based on many factors. Factors we choose to make decisions on by usage of independent thought.*

Superior powers of mind.
*Ambiguous, and without clear definition.*

Protocol.