An Etymological Dictionary of Astronomy and Astrophysics

1. The highest executive officer of a modern republic, as the Chief Executive of the United States (often initial capital letter).
   

2. An officer appointed or elected to preside over an organized body of persons (Dictionary.com).

Etymology (EN): → preside; → -ent.

Etymology (PE): Farneštgâr, from farnešt, present stem of farneštidan, → preside, + agent noun suffix -gâr, → -or, on the model of âmuzgâr “teacher.”