excellence

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

• noun The state, quality, or condition of excelling; superiority.
• noun Something in which one excels.
• noun Excellency.

from The Century Dictionary.

• noun The state of excelling in anything or of possessing good qualities in an unusual or eminent degree; merit; goodness; virtue; superiority; eminence.
• noun A mark or trait of superiority; a valuable quality; anything highly laudable, meritorious, or virtuous in persons, or valuable and esteemed in things; a merit.
• noun Same as excellency, 2.

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

• noun The quality of being excellent; state of possessing good qualities in an eminent degree; exalted merit; superiority in virtue.
• noun An excellent or valuable quality; that by which any one excels or is eminent; a virtue.
• noun A title of honor or respect; -- more common in the form excellency.

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

• noun The quality of being excellent; state of possessing good qualities in an eminent degree; exalted merit; superiority in virtue.
• noun Something in which one excels.
• noun An excellent or valuable quality; that by which any one excels or is eminent; a virtue.

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

• noun the quality of excelling; possessing good qualities in high degree
• noun an outstanding feature; something in which something or someone excels