tet·rarch 
(tĕträrk′, tēträrk′)
(tĕträrk′, tēträrk′)n.
1.
a. A subordinate ruler.
b. One of four joint rulers.
2. A governor of one of four divisions of a country or province, especially in the ancient Roman Empire.
3. The commander of a subdivision of a phalanx in ancient Greece.
[Middle English tetrarche, a Roman tetrarch, from Old French, from Late Latin tetrarcha, from Latin tetrarchēs, from Greek tetrarkhēs : tetra-, tetra- + -arkhēs, -arch.]
te·trarchic (tĕ-trärkĭk, tē-) adj.
- lower criticism
- Lower Egypt
- lower esophageal sphincter
- Lower Forty-Eight
- loweringly
- Lower Michigan
- Lower Michigan
- lowermost
- Lower Palatinate
- Lower Peninsula
- Lower Rhine
- Lower Sorbian
- lower the boom
- Lower Tunguska
- lower world
- lowery
- lowest common denominator
- lowest common multiple
- lowest terms
- low-fi
- low fidelity
- low-fidelity
- low frequency
- low gear
- Low German