What is the Intellect? Permit me to quote by way of answer a short paragraph from the introduction to my recently published Schuon Reader. I don’t mean to suggest that this is the best possible response to your question—far from it—but it has the potential advantage of eliciting or provoking the meaning (as I understand it) while defining it.

“The Intellect is a power of immediate or intuitive discernment, unobstructed by the boundaries of physical objects and unaffected by the limitations of historical circumstance. In contrast with the reason or discursive intelligence, the Intellect enables us to see what is so, not as a conclusion conceptually derived from a premise, but with the immediacy of perception—or ‘combustion’ perhaps, to recall Plato’s ‘leaping spark’ (Epistle VII). It is a direct apprehension of being as object by virtue of being as subject, an apprehension that ‘comes into being’ when the mind attends to itself and to what makes it attend, and when in this way it enters into an ‘other’ that is essentially inward, there to know God. But not just any God or God in any mode: To see God truly is to see that there is within Him something other than God that ‘is’ God nonetheless, which is our seeing—and which our thinking, even in its most skeptical forms, has involved all along, though we ‘knew Him not’ (John 1:10).

I encourage you to think this “definition”, and not just think about it.