intellectual

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Of or relating to the intellect.
2. adj. Rational rather than emotional.
3. adj. Appealing to or engaging the intellect: an intellectual book; an intellectual problem.
4. adj. Having or showing intellect, especially to a high degree. See Synonyms at intelligent.
5. adj. Given to activities or pursuits that require exercise of the intellect.
6. n. An intellectual person.

Century Dictionary and Cyclopedia

1. Of, pertaining to, or of the nature of intellect or understanding; belonging to the mind; performed by the understanding; appealing to or engaging the intellect or the higher capacities of man; mental: as, intellectual powers or operations; intellectual amusements.
2. Perceived by the intellect; existing in the understanding; ideal.
3. Having intellect, or the power of understanding; characterized by intellect, or the capacity for the higher forms of knowledge: as, an intellectual being.
4. n. The intellect or understanding; mental powers or faculties: commonly in the plural.

Wiktionary

1. adj. Belonging to, or performed by, the intellect; mental; as, intellectual powers, activities, etc.
2. adj. 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.
3. adj. Suitable for exercising the intellect; formed by, and existing for, the intellect alone; perceived by the intellect; as, intellectual employments.
4. adj. Relating to the understanding; treating of the mind; as, intellectual philosophy, sometimes called "mental" philosophy.
5. n. An intelligent, learned person, especially one who discourses about learned matters.
6. n. archaic The intellect or understanding; mental powers or faculties.

GNU Webster's 1913

1. adj. Belonging to, or performed by, the intellect; mental.
2. adj. Endowed with intellect; having the power of understanding; having capacity for the higher forms of knowledge or thought; characterized by intelligence or mental capacity.
3. adj. Suitable for exercising the intellect; formed by, and existing for, the intellect alone; perceived by the intellect.
4. adj. Relating to the understanding; treating of the mind.
5. n. The intellect or understanding; mental powers or faculties.
6. n. A learned person or one of high intelligence one who places greatest value on activities requiring exercise of the intelligence, such as study, complex forms of knowledge, literature and aesthetic matters, reflection and philosophical speculation; a member of the intelligentsia.

WordNet 3.0

1. n. a person who uses the mind creatively
2. adj. appealing to or using the intellect
3. adj. of or associated with or requiring the use of the mind
4. adj. involving intelligence rather than emotions or instinct