Intellectual

01 a. Belonging to, or performed by, the intellect; mental; as, intellectual powers, activities, etc.

1.
Belonging to, or performed by, the intellect; mental; as, intellectual powers, activities, etc.
“Logic is to teach us the right use of our reason or intellectual powers.” — I. Watts.
2.
Endowed with intellect; having the power of understanding; having capacity for the higher forms of knowledge or thought; characterized by intelligence or mental capacity; as, an intellectual person.
“Who would lose, Though full of pain, this intellectual being, Those thoughts that wander through eternity?” — Milton.
3.
Suitable for exercising the intellect; formed by, and existing for, the intellect alone; perceived by the intellect; as, intellectual employments.
4.
Relating to the understanding; treating of the mind; as, intellectual philosophy, sometimes called “mental” philosophy.

02 n. The intellect or understanding; mental powers or faculties.

1.
The intellect or understanding; mental powers or faculties.
“Her husband, for I view far round, not nigh, Whose higher intellectual more I shun.” — Milton.

“I kept her intellectuals in a state of exercise.” — De Quincey.
2.
A learned person or one of high intelligence;