Incongruousness and Unknown quantity

Incongruousness noun - The quality of disagreeing; being unsuitable and inappropriate.

Unknown quantity and incongruousness are semantically related. In some cases you can use "Unknown quantity" instead a noun "Incongruousness".

Unknown quantity noun - A factor in a given situation whose bearing and importance is not apparent.

Incongruousness and unknown quantity are semantically related. Sometimes you can use "Incongruousness" instead a noun phrase "Unknown quantity".