cadet

Short definition from Wiktionary

Noun

1. 1
   A student at a military school who is training to be an officer.
2. 2
   A younger or youngest son, who would not inherit as a firstborn son would.
3. 3
   Junior. (See also the heraldic term cadency.)
4. 4
   A young man who makes a business of ruining girls to put them in brothels.
5. 5
   A young gentleman learning sheep farming at a station; also, any young man attached to a sheep station.
6. 6
   A participant in a cadetship.

Proper noun

1. 1
   A surname from French.