congruence

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

• noun Agreement, harmony, conformity, or correspondence.
• noun An instance of this.
• noun The state of being congruent.
• noun A statement that two quantities are congruent.

from The Century Dictionary.

• noun In geometry, identity in shape and size. Its symbol is ≡.
• noun In line geometry, a set of ∞ lines, such that any two given conditions determine a definite finite number of lines of the set.
• noun Suitableness or appropriateness of one thing to another; agreement; consistency. Also congruency.
• noun Tn mathematics, a relation between three numbers such that the difference between two of them, which are said to be congruent, is divisible by the third, which is called the modulus.
• noun In grammar, concord; agreement.
• noun Same as congruency, 2.

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

• noun Suitableness of one thing to another; agreement; consistency.

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

• noun The quality of agreeing or corresponding; being suitable and appropriate.
• noun mathematics, number theory a relation between two numbers indicating they give the same remainder when divided by some given number
• noun mathematics, geometry being isometric — roughly, the same size and shape
• noun algebra more generally: any equivalence relation defined on an algebraic structure which is preserved by operations defined by the structure

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

• noun the quality of agreeing; being suitable and appropriate