9 letters · 10 points in Scrabble
noun any of various controls or devices for regulating or controlling fluid flow, pressure, temperature, etc.
noun an official responsible for control and supervision of a particular activity or area of public interest
noun a control that maintains a steady speed in a machine (as by controlling the supply of fuel)
originEtymology tree English regulate English -or English regulator From regulate + -or.
Etymology from Wiktionary, CC BY-SA 3.0