Full Idea
Intuition apprehends the definitions which cannot be logically demonstrated.
Clarification
'Intuition' is the Greek word 'nous'
Gist of Idea
Intuition grasps the definitions that can't be proved
Source
Aristotle (Nicomachean Ethics [c.334 BCE], 1142a25)
Book Reference
Aristotle: 'Ethics (Nicomachean)', ed/tr. ThomsonJ A K/TredennickH [Penguin 1976], p.215
A Reaction
Nice to see that (like me) he has a positive view of intuition. I'm not sure how you would 'prove' a definition of the hidden nature of a thing (which is usually taken to be hidden).