shoot down vs rip

shoot down is not a noun while rip is a noun.

Word	Noun	Adjective	Verb	Adverb
shoot down	No	No	Yes	No
rip	Yes	No	Yes	No

As verbs, rip is a hyponym of shoot down; that is, rip is a word with a more specific, narrower meaning than shoot down:

shoot down (noun)	rip (noun)
	the act of rending or ripping or splitting something
	a stretch of turbulent water in a river or the sea caused by one current flowing into or across another current
	an opening made forcibly as by pulling apart
	a dissolute man in fashionable society

shoot down (verb)	rip (verb)
shoot at and force to come down	criticize or abuse strongly and violently
move quickly and violently	tear or be torn violently
thwart the passage of	cut (wood) along the grain
	move precipitously or violently
	take without the owner's consent