junior vs senior

junior and senior both are nouns.

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

junior (noun)	senior (noun)
the younger of two persons	an undergraduate student during the year preceding graduation
a third-year undergraduate	a person who is older than you are
term of address for a disrespectful and annoying male

junior (adjective)	senior (adjective)
younger; lower in rank; shorter in length of tenure or service	older; higher in rank; longer in length of tenure or service
used of the third or next to final year in United States high school or college	used of the fourth and final year in United States high school or college
including or intended for youthful persons	advanced in years; (`aged' is pronounced as two syllables)