spying vs uncovering

spying and uncovering both are nouns.

Word	Noun	Adjective	Verb	Adverb
spying	Yes	No	No	No
uncovering	Yes	No	No	No

As nouns, uncovering is a hypernym of spying; that is, uncovering is a word with a broader meaning than spying:

Other hypernyms of spying include discovery, find.

spying (noun)	uncovering (noun)
the act of keeping a secret watch for intelligence purposes	the act of discovering something
keeping a secret or furtive watch	the removal of covering
the act of detecting something; catching sight of something