take down vs reef

take down is not a noun while reef is a noun.

Word	Noun	Adjective	Verb	Adverb
take down	No	No	Yes	No
reef	Yes	No	Yes	No

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

Other hyponyms of take down include depress, dip, incline.

take down (noun)	reef (noun)
	one of several strips across a sail that can be taken in or rolled up to lessen the area of the sail that is exposed to the wind
	a submerged ridge of rock or coral near the surface of the water

take down (verb)	reef (verb)
make a written note of	roll up (a portion of a sail) in order to reduce its area
tear down so as to make flat with the ground	reduce (a sail) by taking in a reef
reduce in worth or character, usually verbally	lower and bring partially inboard
move something or somebody to a lower position