I. ˈsēnyə(r) noun
( -s )
Etymology: Middle English, from Latin, from senior older, elder
1.
a. : an elderly or old person
know how to make us seniors very unnecessary — R.W.Emerson
the seniors were active in the local affairs — Roy Lewis & Angus Maude
b. : a person accorded distinction or deference in respect for his age : elder III 3
c. : one who is older than another
thrown among his seniors in the upper grades of the school
d. Britain : a student in a senior school
2.
a. : a person holding a position of higher standing in a hierarchy of ranks
as his senior he would of course command the entire force — H.E.Scudder
b. : a senior fellow of a college at an English university ; specifically : a member of a governing council of a college (as at Trinity College, Cambridge)
c. : head boy
d. : a student in his last year before graduating from an educational institution of secondary or higher level
a high school senior
college seniors
a senior in law school
3. : a sexually mature animal
4. : eldest hand ; specifically : the player at the left of the declarer in bridge
II. adjective
Etymology: Middle English, from Latin, compar. of sen-, senex old; akin to Gothic sineigs old, sinista eldest, Old Norse sina old grass, Greek henos old, Sanskrit sana
1.
a. : more advanced in age than another : older
senior to her classmate by a full year
having to support … human creatures senior and junior to themselves — F.L.Allen
— abbr. Sr or sr ; used chiefly and often cap. to distinguish a father with the same given name as his son; opposed to junior
b. : advanced in age
too senior to begin to try for Cabinet office — John Buchan
c. : earliest in date of origin or founding
piracy, one of the senior sins of the human race — George Woodbury
the senior organization of its kind — Thurston Dart
d. : ranking above another in length of service
the senior senator of the state
the senior members of the committee
specifically : having more seniority than another
the most senior airline pilots flying on the more desirable assignments — H.R.Northrup
2.
a. : higher in standing or rank especially in a hierarchy of ranks : superior
the senior scholars of the university
lieutenant senior grade
senior scientists
the more senior the officer, the more time he has — G.S.Patton
young for so senior a post — William Ridsdale
b. : associated with one or more others in a leading or primary role
senior partner
senior member of a law firm
specifically : mentioned first and given major credit among collaborating authors (as of a scientific paper)
the name of the senior author will be widely recognized — Paul Woodring
3. : of or relating to seniors in an educational institution
the senior class
the senior prom
4.
a. of a bond : having a lien preference prior to other bonds
b. of a preferred stock : having a dividend preference prior to other stocks
a senior security