approximation

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

• noun The act, process, or result of approximating.
• noun Mathematics An inexact result adequate for a given purpose.

from The Century Dictionary.

• noun The act of approximating; a drawing, moving, or advancing near in space, position, degree, or relation; approach; proximity.
• noun In mathematics and physical: A continual approach to a true result; the process by which the value of a quantity is calculated with continually increasing exactness without ever being actually ascertained
• noun A result so obtained; a result which is not rigorously exact, but is so near the truth as to be sufficient for a given purpose.

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

• noun The act of approximating; a drawing, advancing or being near; approach; also, the result of approximating.
• noun An approach to a correct estimate, calculation, or conception, or to a given quantity, quality, etc.
• noun A continual approach or coming nearer to a result.
• noun A value that is nearly but not exactly correct.

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

• noun The act, process or result of approximating.
• noun mathematics An imprecise solution or result that is adequate for a defined purpose.
• noun medicine The act of bringing together the edges of tissue to be sutured.

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

• noun an approximate calculation of quantity or degree or worth
• noun the act of bringing near or bringing together especially the cut edges of tissue
• noun the quality of coming near to identity (especially close in quantity)
• noun an imprecise or incomplete account