Congruency is the alignment of all output channels in a communication. E.g. the words, the tone of voice, the gestures are all communicating the same or similar message. Incongruency is the result of conflicting messages, eg saying "Yes, I'm sure" in a soft questioning voice ending with an upward inflection.

The state or quality of being congruous; the relation or agreement between things; fitness; harmony; correspondence; consistency.

That, in an imperfectly good persons, which renders it suitable for God to bestow on him gifts of grace.

the quality of agreeing; being suitable and appropriate

Coincidence, as that of lines or figures laid over one another.