prin·ci·pate \ˈprin(t)səˌpāt, -səpə̇t\noun (-s) Etymology: Middle English principat, from Latin principatus, from princip-, princeps first person, prince + -atus -ate — more at prince 1.: princely power : supreme rule 2.obsolete a.: principality 4b b.: a principal person : prince 3.: principality 3 4.: the power or term of a Roman princeps