spying vs catching

spying and catching both are nouns.

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

As nouns, spying and catching are synonyms defined as:

spying and catching: the act of detecting something; catching sight of something

Other synonyms of spying include detection, espial, spotting.

spying (noun)	catching (noun)
the act of keeping a secret watch for intelligence purposes	(baseball) playing the position of catcher on a baseball team
keeping a secret or furtive watch	the act of detecting something; catching sight of something
the act of detecting something; catching sight of something	becoming infected

spying (adjective)	catching (adjective)
	(of disease) capable of being transmitted by infection