senior vs superior

senior and superior both are nouns.

Word	Noun	Adjective	Verb	Adverb
senior	Yes	Yes	No	No
superior	Yes	Yes	No	No

senior (noun)	superior (noun)
an undergraduate student during the year preceding graduation	a character or symbol set or printed or written above and immediately to one side of another character
a person who is older than you are	one of greater rank or station or quality
	the head of a religious community
	a combatant who is able to defeat rivals

senior (adjective)	superior (adjective)
older; higher in rank; longer in length of tenure or service	written or printed above and to one side of another character
used of the fourth and final year in United States high school or college	of or characteristic of high rank or importance
advanced in years; (`aged' is pronounced as two syllables)	of high or superior quality or performance
	having an orbit farther from the sun than the Earth's orbit
	(sometimes followed by `to') not subject to or influenced by
	having a higher rank
	(often followed by `to') above being affected or influenced by