strike vs down

strike and down both are nouns.

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

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

strike (noun)	down (noun)
a group's refusal to work in protest against low pay or bad work conditions	(American football) a complete play to advance the football
a score in tenpins: knocking down all ten with the first ball	soft fine feathers
an attack that is intended to seize or inflict damage on or destroy an objective	fine soft dense hair (as the fine short hair of cattle or deer or the wool of sheep or the undercoat of certain dogs)
a conspicuous success	(usually plural) a rolling treeless highland with little soil
(baseball) a pitch that the batter swings at and misses, or that the batter hits into foul territory, or that the batter does not swing at but the umpire judges to be in the area over home plate and between the batter's knees and shoulders
a gentle blow

strike (adjective)	down (adjective)
	being or moving lower in position or less in some value
	filled with melancholy and despondency
	extending or moving from a higher to a lower place
	becoming progressively lower
	not functioning (temporarily or permanently)
	lower than previously
	shut
	being put out in a game of baseball
	understood perfectly

strike (verb)	down (verb)
cause to form (an electric arc) between electrodes of an arc lamp	improve or perfect by pruning or polishing
arrive at after reckoning, deliberating, and weighing	bring down or defeat (an opponent)
indicate (a certain time) by striking	drink down entirely
make a strategic, offensive, assault against an enemy, opponent, or a target	eat up completely, as with great appetite
deliver a sharp blow, as with the hand, fist, or weapon	cause to come or go down
hit against; come into sudden contact with	shoot at and force to come down
affect or afflict suddenly, usually adversely
produce by manipulating keys or strings of musical instruments
remove by erasing or crossing out or as if by drawing a line
pierce with force
smooth with a strickle
hook by a pull on the line
produce by ignition or a blow
form by stamping, punching, or printing
disassemble a temporary structure, such as a tent or a theatrical set
have an emotional or cognitive impact upon
drive something violently into a location
occupy or take on
cause to experience suddenly
find unexpectedly
stop work in order to press demands
attain
touch or seem as if touching visually or audibly

strike (adverb)	down (adverb)
	spatially or metaphorically from a higher to a lower level or position
	away from a more central or a more northerly place
	paid in cash at time of purchase
	in an inactive or inoperative state
	to a lower intensity
	from an earlier time