a. [ L. senior, compar. of senex, gen. senis, old. See Sir. ] 1. More advanced than another in age; prior in age; elder; hence, more advanced in dignity, rank, or office; superior; as, senior member; senior counsel. [ 1913 Webster ]

2. Belonging to the final year of the regular course in American colleges, or in professional schools. [ 1913 Webster ]

n. 1. A person who is older than another; one more advanced in life. [ 1913 Webster ]

2. One older in office, or whose entrance upon office was anterior to that of another; one prior in grade. [ 1913 Webster ]

3. An aged person; an older. Dryden. [ 1913 Webster ]

Each village senior paused to scan,
And speak the lovely caravan. Emerson. [ 1913 Webster ]

4. One in the fourth or final year of his collegiate course at an American college; -- originally called senior sophister; also, one in the last year of the course at a professional schools or at a seminary. [ 1913 Webster ]

n. The quality or state of being senior. [ 1913 Webster ]

v. i. To exercise authority; to rule; to lord it. [ R. ] Fairfax. [ 1913 Webster ]

n. Seniority. [ Obs. ] Shak. [ 1913 Webster ]