Emily Dickinson Lexicon

CA-DET', n. [Fr. cadet; It. cadetto; Sp. cadete. In French, properly the second son. Gebelin. But in general, the younger son or brother, or the youngest.]

1. The younger or youngest son. – Brown.
2. A gentleman who carries arms in a regiment, as a private man, with a view to acquire military skill, and obtain a commission. His service is voluntary, but he receives pay, and thus is distinguished from a volunteer. – Encyc.
3. A young man in a military school.