Meaning of SENIOR in English

noun an aged person; an older.

2. senior ·noun a person who is older than another; one more advanced in life.

3. senior ·adj belonging to the final year of the regular course in american colleges, or in professional schools.

4. senior ·noun one older in office, or whose entrance upon office was anterior to that of another; one prior in grade.

5. senior ·adj more advanced than another in age; prior in age; elder; hence, more advanced in dignity, rank, or office; superior; as, senior member; senior counsel.

6. senior ·noun 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.

Webster English vocab.      Английский словарь Webster.