pursual vs tailing

pursual and tailing both are nouns.

Word	Noun	Adjective	Verb	Adverb
pursual	Yes	No	No	No
tailing	Yes	No	No	No

As nouns, tailing is a hyponym of pursual; that is, tailing is a word with a more specific, narrower meaning than pursual:

Other hyponyms of pursual include tracking, trailing, shadowing, stalk, stalking.

pursual (noun)	tailing (noun)
the act of pursuing in an effort to overtake or capture	the act of following someone secretly