Available Definitions:
1) a. - Less advanced in age than another; younger.
2) a. - Lower in standing or in rank; later in office; as, a junior partner; junior counsel; junior captain.
3) a. - Composed of juniors, whether younger or a lower standing; as, the junior class; of or pertaining to juniors or to a junior class. See Junior , n., 2.
4) n. - Belonging to a younger person, or an earlier time of life.
5) n. - A younger person.
6) n. - Hence: One of a lower or later standing; specifically, in American colleges, one in the third year of his course, one in the fourth or final year being designated a senior; in some seminaries, one in the first year, in others, one in the second year, of a three years' course.