redundance vs redundancy

redundance and redundancy both are nouns.

Word	Noun	Adjective	Verb	Adverb
redundance	Yes	No	No	No
redundancy	Yes	No	No	No

As nouns, redundance and redundancy are synonyms defined as:

redundance and redundancy: the attribute of being superfluous and unneeded

redundance (noun)	redundancy (noun)
the attribute of being superfluous and unneeded	repetition of an act needlessly
	the attribute of being superfluous and unneeded
	(electronics) a system design that duplicates components to provide alternatives in case one component fails
	repetition of messages to reduce the probability of errors in transmission