tetrarch

noun

te·​trarch ˈte-ˌträrk  ˈtē- 

1

: a governor of the fourth part of a province

2

: a subordinate prince

tetrarchic

te-ˈträr-kik 

tē-

adjective

Word History

Etymology

Middle English, from Latin tetrarcha, from Greek tetrarchēs, from tetra- + -archēs -arch

First Known Use

12th century, in the meaning defined at sense 1