The quality of being isometric — roughly, the same measure and shape.
The quality of agreeing or corresponding; being suitable and appropriate.
Matrix similarity by an orthogonal matrix.
A relation between two numbers indicating they give the same remainder when divided by some given number.
More generally: any equivalence relation defined on an algebraic structure which is preserved by operations defined by the structure.
The quality of being the same; identity.
A tiring lack of variety; monotony.
The state of being equivalent; equality.