catching vs spying

catching and spying both are nouns.

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

As nouns, catching and spying are synonyms defined as:

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

Other synonyms of catching include detection, espial, spotting.

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

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