Device That Controls the Flow of Fuel to an Engine
This page is the CodyCross answer for the clue below from Photography, Group 2016, Puzzle 3 (Optical Zoom).
Question is: Device That Controls the Flow of Fuel to an Engine
and the answer is: THROTTLE
Word Meaning:
THROTTLE — A valve that regulates the supply of fuel-air mixture to an internal combustion engine and thus controls its speed; a similar valve that controls the air supply to an engine.
Definitions from Wiktionary.