older or elder (usually designating the older of two men bearing the same name, as a father whose son is named after him, often written as Sr. or sr. following the name): I would like to see the senior Mr. Hansen Mr. Edward Andrew Hansen, Sr. Compare junior(def. 1).
2.
of earlier appointment or admission, as to an office, status, or rank: a senior partner.
3.
of higher or the highest rank or standing.
4.
(in American schools, colleges, and universities) of or pertaining to students in their final year or to their class.
5.
(in certain American colleges and universities) of or pertaining to the final two years of education, during which a student specializes in a certain field of study.
a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.
a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.
a chattering or flighty, light-headed person.
a fool or simpleton; ninny.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
late 13c., from L. senior "older," comparative of senex (gen. senis) "old," from PIE base *sen- (see senile). Original use in English was as addition to a personal name when father and son had the same name; meaning "higher in rank, longer in service" first recorded 1510s.
The L. word yielded titles of respect in many languages, cf. Fr. sire, Sp. señor, It. signor. Noun sense of "fourth-year student" is from 1741, from earlier general sense of "advanced student" (1610s). Seniority "priority on office or service" is from mid-15c. Senior citizen first recorded 1938, Amer.Eng.