Princeps
Defined in 3 dictionaries — Ballentine's (1916), Black's (1910), Kinney (1893)
Ballentine's Law Dictionary
James A. Ballentine · 1916
A chief; a leader; the emperor.
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
Lat.
In the civil law. The prince; the emperor.
A Law Dictionary and Glossary
George C. Kinney · 1893
Lat.
In old English law. The king. Princeps et respublica ex justa causa possunt rem meam auferre: the king and the state [the government] may take my property for just cause.
In the civil law. The prince; the emperor. Princeps legibus solutus est: the emperor is released from the laws; is not bound by the laws.