abstraction

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

• noun The act of abstracting or the state of having been abstracted.
• noun An abstract concept, idea, or term.
• noun An abstract quality.
• noun Preoccupation; absent-mindedness.
• noun An abstract work of art.

from The Century Dictionary.

• noun In geology, the tapping of the head waters of one stream by another the erosive action of which is more rapid.
• noun The act of taking away or separating; the act of withdrawing, or the state of being withdrawn; withdrawal, as of a part from a whole, or of one thing from another.
• noun The act of abstracting or concentrating the attention on a part of a complex idea and neglecting the rest or supposing it away; especially, that variety of this procedure by which we pass from a more to a less determinate concept, from the particular to the general; the act or process of refining or sublimating.
• noun A concept which is the product of an abstracting process; a metaphysical concept; hence, often, an idea which cannot lead to any practical result; a theoretical, impracticable notion; a formality; a fiction of metaphysics.
• noun Inattention to present objects; the state of being engrossed with any matter to the exclusion of everything else; absence of mind: as, a fit of abstraction.
• noun In distillation, the separation of volatile parts from those which are fixed.

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

• noun The act of abstracting, separating, or withdrawing, or the state of being withdrawn; withdrawal.
• noun (Metaph.) The act process of leaving out of consideration one or more properties of a complex object so as to attend to others; analysis. So, also, when it considers whiteness, softness, virtue, existence, as separate from any particular objects.
• noun An idea or notion of an abstract, or theoretical nature.
• noun A separation from worldly objects; a recluse life.
• noun Absence or absorption of mind; inattention to present objects.
• noun Modern The taking surreptitiously for one's own use part of the property of another; purloining.
• noun (Chem.) A separation of volatile parts by the act of distillation.

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

• noun chemistry A separation of volatile parts by the act of distillation.
• noun An idea of an unrealistic or visionary nature.
• noun The result of mentally abstracting an idea; the results of said process.
• noun geology The merging of two river valleys by the larger of the two deepening and widening so much so, as to assimilate the smaller.
• noun computing Any generalization technique that ignores or hides details to capture some kind of commonality between different instances for the purpose of controlling the intellectual complexity of engineered systems, particularly software systems.
• noun computing Any intellectual construct produced through the technique of abstraction.

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

• noun a general concept formed by extracting common features from specific examples
• noun a concept or idea not associated with any specific instance
• noun an abstract painting
• noun the process of formulating general concepts by abstracting common properties of instances
• noun the act of withdrawing or removing something
• noun preoccupation with something to the exclusion of all else