governor vs viceroy

governor and viceroy both are nouns.

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

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

governor: the head of a state government
viceroy: governor of a country or province who rules as the representative of his or her king or sovereign

Other hyponyms of governor include bey, eparch, governor general, military governor, nabob, nawab, proconsul, satrap, vicereine.

governor (noun)	viceroy (noun)
a control that maintains a steady speed in a machine (as by controlling the supply of fuel)	showy American butterfly resembling the monarch but smaller
the head of a state government	governor of a country or province who rules as the representative of his or her king or sovereign