"Junior" is a word in LAW AND LEGAL, ENGLISH

Younger. This has been held to be no part of a man's name, but an addition by use, and a convenient distinction be-tween a father and son of the same name. Cobh ▼. Lucas, 15 Pick. (Mass.) 9; People ▼. Collins, 7 Johns. (N. Y.) 552; Padgett v. Lawrence, 10 Paige (N. Y.) 177, 40 Am. Dec. 232; Prentiss v. Blake, 34 VL 460

Less advanced in age than another; younger.

Lower in standing or in rank; later in office; as, a junior
partner; junior counsel; junior captain.

A younger person.

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.

Belonging to a younger person, or an earlier time of life.

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.