shoot vs shoot down

shoot is a noun but shoot down is not a noun.

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

As verbs, shoot and shoot down are synonyms defined as:

Other synonyms of shoot include buck, charge, tear.

shoot (noun)	shoot down (noun)
the act of shooting at targets
a new branch

shoot (verb)	shoot down (verb)
give an injection to	shoot at and force to come down
produce buds, branches, or germinate	move quickly and violently
measure the altitude of by using a sextant	thwart the passage of
record on photographic film
make a film or photograph of something
utter fast and forcefully
fire a shot; release
hit with a missile from a weapon
score
spend frivolously and unwisely
force or drive (a fluid or gas) into by piercing
throw or propel in a specific direction or towards a specific objective
throw dice, as in a crap game
variegate by interweaving weft threads of different colors
run or move very quickly or hastily
move quickly and violently
send forth suddenly, intensely, swiftly
cause a sharp and sudden pain in
kill by firing a missile
emit (as light, flame, or fumes) suddenly and forcefully