drop vs go down

drop is a noun but go down is not a noun.

Word	Noun	Adjective	Verb	Adverb
drop	Yes	No	Yes	No
go down	No	No	Yes	No

As verbs, go down is a hypernym of drop; that is, go down is a word with a broader meaning than drop:

Other hypernyms of drop include decline, wane.

As verbs, go down is a hypernym of drop; that is, go down is a word with a broader meaning than drop:

Other hypernyms of drop include come down, descend, fall.

drop (noun)	go down (noun)
the act of dropping something
a central depository where things can be left or picked up
a curtain that can be lowered and raised onto a stage from the flies; often used as background scenery
a sudden sharp decrease in some quantity
a free and rapid descent by the force of gravity
a predetermined hiding place for the deposit and distribution of illicit goods (such as drugs or stolen property)
a steep high face of rock
a small indefinite quantity (especially of a liquid)
a shape that is spherical and small

drop (verb)	go down (verb)
give birth; used for animals	grow smaller
grow progressively worse	stop operating
go down in value	be defeated
stop pursuing or acting	be ingested
change from one level to another	go under
lower the pitch of (musical notes)	disappear beyond the horizon
fall or sink into a state of exhaustion or death	move downward and lower, but not necessarily all the way
leave undone or leave out	be recorded or remembered
omit (a letter or syllable) in speaking or writing
utter with seeming casualness
lose (a game)
take (a drug, especially LSD), by mouth
remove (cargo, people, etc.) from and leave
to remove
cause to fall by or as if by delivering a blow
let or cause to fall in drops
to fall vertically
let fall to the ground
fall or descend to a lower place or level
pay out
stop associating with
terminate an association with
hang loosely