perception

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

• noun The process of perceiving something with the senses.
• noun An instance of this.
• noun The process or state of being aware of something.
• noun Insight or knowledge gained by thinking.
• noun The capacity for such insight or knowledge.
• noun An insight or point of knowledge.
• noun An interpretation or impression; an opinion or belief.

from The Century Dictionary.

• noun Originally, and most commonly down to the middle of the eighteenth century, cognition; thought and sense in general, whether the faculty, the operation, or the resulting idea.
• noun The mental faculty, operation, or resulting construction of the imagination, of gaining knowledge by virtue of a real action of an object upon the mind.
• noun An immediate judgment founded on sense or other real action of the object upon the mind, more or less analogous to what takes place in vision.
• noun In law, participation in receipts; community of interest in income: as, the perception of profits.

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

• noun The act of perceiving; cognizance by the senses or intellect; apperhension by the bodily organs, or by the mind, of what is presented to them; discernment; apperhension; cognition.
• noun (Metaph.) The faculty of perceiving; the faculty, or peculiar part, of man's constitution by which he has knowledge through the medium or instrumentality of the bodily organs; the act of apperhending material objects or qualities through the senses; -- distinguished from conception.
• noun obsolete The quality, state, or capability, of being affected by something external; sensation; sensibility.
• noun obsolete An idea; a notion.

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

• noun Conscious understanding of something.
• noun Vision (ability)
• noun Acuity
• noun That which is detected by the five senses; not necessarily understood (imagine looking through fog, trying to understand if you see a small dog or a cat); also that which is detected within consciousness as a thought, intuition, deduction, etc.

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

• noun knowledge gained by perceiving
• noun a way of conceiving something
• noun becoming aware of something via the senses
• noun the representation of what is perceived; basic component in the formation of a concept
• noun the process of perceiving