TETRARCH Meaning of TETRARCH in English [te.trarch] n [ME, fr. L tetrarcha, fr. Gk tetrarches, fr. tetra- + -arches -arch] (14c) 1: a governor of the fourth part of a province 2: a subordinate prince -- te.trar.chic adj Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012