elegance

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

• noun Refinement, grace, and beauty in movement, appearance, or manners.
• noun Tasteful opulence in form, decoration, or presentation.
• noun Restraint and grace of style.
• noun Scientific exactness and precision.
• noun Something elegant.

from The Century Dictionary.

• noun The state or quality of being elegant; beauty resulting from perfect propriety or from exact fitness, symmetry, or the like; refinement of manner, quality, or appearance: as, elegance of dress.
• noun That which pleases by its nicety, symmetry, purity, or beauty; an elegancy: as, the elegances of polite society.

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

• noun The state or quality of being elegant; beauty as resulting from choice qualities and the complete absence of what deforms or impresses unpleasantly; grace given by art or practice; fine polish; refinement; -- said of manners, language, style, form, architecture, etc.
• noun That which is elegant; that which is tasteful and highly attractive.

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

• noun Grace, refinement, and beauty in movement, appearance, or manners
• noun Restraint and grace of style
• noun The beauty of an idea characterized by minimalism and intuitiveness while preserving exactness and precision
• noun countable A refinement or luxury

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

• noun a quality of neatness and ingenious simplicity in the solution of a problem (especially in science or mathematics)
• noun a refined quality of gracefulness and good taste