blow out vs stub

blow out is not a noun while stub is a noun.

Word	Noun	Adjective	Verb	Adverb
blow out	No	No	Yes	No
stub	Yes	No	Yes	No

As verbs, stub is a hyponym of blow out; that is, stub is a word with a more specific, narrower meaning than blow out:

Other hyponyms of blow out include crush out, extinguish, press out, stub out, douse, put out.

blow out (noun)	stub (noun)
	the small unused part of something (especially the end of a cigarette that is left after smoking)
	a torn part of a ticket returned to the holder as a receipt
	the part of a check that is retained as a record
	a short piece remaining on a trunk or stem where a branch is lost
	a small piece

blow out (verb)	stub (verb)
melt, break, or become otherwise unusable	strike (one's toe) accidentally against an object
put out, as of fires, flames, or lights	clear of weeds by uprooting them
erupt in an uncontrolled manner	extinguish by crushing
	pull up (weeds) by their roots