n. a person who is older than you are

n. an undergraduate student during the year preceding graduation

adj. used of the fourth and final year in United States high school or college; "the senior prom"

adj. advanced in years; (`aged' is pronounced as two syllables); "aged members of the society"; "elderly residents could remember the construction of the first skyscraper"; "senior citizen"

adj. older; higher in rank; longer in length of tenure or service; "senior officer"