spy vs supervise

spy is a noun but supervise is not a noun.

Word	Noun	Adjective	Verb	Adverb
spy	Yes	No	Yes	No
supervise	No	No	Yes	No

As verbs, supervise is a hypernym of spy; that is, supervise is a word with a broader meaning than spy:

Other hypernyms of spy include monitor.

spy (noun)	supervise (noun)
(military) a secret agent hired by a state to obtain information about its enemies or by a business to obtain industrial secrets from competitors
a secret watcher; someone who secretly watches other people

spy (verb)	supervise (verb)
secretly collect sensitive or classified information; engage in espionage	keep tabs on; keep an eye on; keep under surveillance
watch, observe, or inquire secretly	watch and direct
catch sight of
catch sight of; to perceive with the eyes