intellectual

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of or relating to the intellect.
• adjective Rational rather than emotional.
• adjective Appealing to or engaging the intellect.
• adjective Having or showing intellect, especially to a high degree. synonym: intelligent.
• adjective Given to activities or pursuits that require exercise of the intellect.
• noun An intellectual person.

from The Century Dictionary.

• 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.
• Perceived by the intellect; existing in the understanding; ideal.
• Having intellect, or the power of understanding; characterized by intellect, or the capacity for the higher forms of knowledge: as, an intellectual being.
• noun The intellect or understanding; mental powers or faculties: commonly in the plural.

from the GNU version of the Collaborative International Dictionary of English.

• noun The intellect or understanding; mental powers or faculties.
• noun A learned person or one of high intelligence
• adjective Belonging to, or performed by, the intellect; mental
• adjective Endowed with intellect; having the power of understanding; having capacity for the higher forms of knowledge or thought; characterized by intelligence or mental capacity.
• adjective Suitable for exercising the intellect; formed by, and existing for, the intellect alone; perceived by the intellect.
• adjective Relating to the understanding; treating of the mind.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

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

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a person who uses the mind creatively
• adjective appealing to or using the intellect
• adjective of or associated with or requiring the use of the mind
• adjective involving intelligence rather than emotions or instinct