imminence vs impendency

imminence and impendency both are nouns.

Word	Noun	Adjective	Verb	Adverb
imminence	Yes	No	No	No
impendency	Yes	No	No	No

As nouns, imminence and impendency are synonyms defined as:

imminence and impendency: the state of being imminent and liable to happen soon

Other synonyms of imminence include forthcomingness, imminency, imminentness, impendence.

imminence (noun)	impendency (noun)
the state of being imminent and liable to happen soon	the state of being imminent and liable to happen soon