precedency vs anteriority

precedency and anteriority both are nouns.

Word	Noun	Adjective	Verb	Adverb
precedency	Yes	No	No	No
anteriority	Yes	No	No	No

As nouns, precedency and anteriority are synonyms defined as:

Other synonyms of precedency include antecedence, antecedency, precedence, priority.

precedency (noun)	anteriority (noun)
the act of preceding in time or order or rank (as in a ceremony)	the quality of being in front or (in lower animals) toward the head
preceding in time	preceding in time
status established in order of importance or urgency