timer vs governor

timer and governor both are nouns.

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

As nouns, governor is a hypernym of timer; that is, governor is a word with a broader meaning than timer:

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

Other hypernyms of timer include regulator.

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