seniority vs higher rank

seniority and higher rank both are nouns.

Word	Noun	Adjective	Verb	Adverb
seniority	Yes	No	No	No
higher rank	Yes	No	No	No

As nouns, seniority and higher rank are synonyms defined as:

seniority and higher rank: higher rank than that of others especially by reason of longer service

Other synonyms of seniority include higher status, senior status.

seniority (noun)	higher rank (noun)
the property of being long-lived	higher rank than that of others especially by reason of longer service
higher rank than that of others especially by reason of longer service