EXECUTIONER. An officer of high rank in the East, commander of the bodyguard who executed the king’s sentence. Potiphar (Gen.37.36 asv footnote) was the “chief of the executioners.” Nebuzaradan (Jer.39.9 asv footnote) and Arioch (Dan.2.14 asv) held this office. In the Gospel record we are told that King Herod sent an executioner (Gr. spekoulatōr, originally a military watch or scout), i.e., one of his bodyguard, to behead [[John the Baptist]] (Mark.6.27).

International Standard Bible Encyclopedia (1915)

ek’-se-kut, ek-se-ku’-shun-er (`asah, "to do," din,"to judge," "decide"; poieo, "to do"; spekoulator, Latin speculator, "an attendant"):

George B. Eager