variance vs variableness

variance and variableness both are nouns.

Word	Noun	Adjective	Verb	Adverb
variance	Yes	No	No	No
variableness	Yes	No	No	No

As nouns, variance and variableness are synonyms defined as:

Other synonyms of variance include variability.

variance (noun)	variableness (noun)
an activity that varies from a norm or standard	the quality of being subject to variation
an official dispensation to act contrary to a rule or regulation (typically a building regulation)
a difference between conflicting facts or claims or opinions
the quality of being subject to variation
the second moment around the mean; the expected value of the square of the deviations of a random variable from its mean value
discord that splits a group
an event that departs from expectations