spy vs descry

spy is a noun but descry is not a noun.

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

As verbs, spy and descry are synonyms defined as:

Other synonyms of spy include espy, spot.

As verbs, descry is a hyponym of spy; that is, descry is a word with a more specific, narrower meaning than spy:

Other hyponyms of spy include espy, spot, spy, detect, discover, find, notice, observe.

spy (noun)	descry (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)	descry (verb)
secretly collect sensitive or classified information; engage in espionage	catch sight of
watch, observe, or inquire secretly
catch sight of
catch sight of; to perceive with the eyes