Not congruous; reciprocally disagreeing; not capable of harmonizing or readily assimilating; inharmonious; inappropriate; unsuitable; not fitting; inconsistent; improper; as, an incongruous remark; incongruous behavior, action, dress, etc.

inconsistent, unharmonious with what is logical or usual within a thing

lacking in harmony or compatibility or appropriateness; "a plan incongruous with reason"; "incongruous behavior"; "a joke that was incongruous with polite conversation"