governor vs timer

governor and timer both are nouns.

Word	Noun	Adjective	Verb	Adverb
governor	Yes	No	No	No
timer	Yes	No	No	No

As nouns, timer is a hyponym of governor; that is, timer is a word with a more specific, narrower meaning than governor:

governor: a control that maintains a steady speed in a machine (as by controlling the supply of fuel)
timer: a regulator that activates or deactivates a mechanism at set times

Other hyponyms of governor include flywheel.

governor (noun)	timer (noun)
a control that maintains a steady speed in a machine (as by controlling the supply of fuel)	a timepiece that measures a time interval and signals its end
the head of a state government	a regulator that activates or deactivates a mechanism at set times
	(sports) an official who keeps track of the time elapsed