This word is commonly used to refer the congruency in the behaviour that is consistency between the goals, values, and attitudes projected and the actual behavior observed.
It came from a latin verb congruere that is "to come together" comparing two things being consistent with each other.
Mathematical Meaning:
In geometry, two figures or objects are congruent if they have the same shape and size, or if one has the same shape and size as the mirror image of the other.