disconnect vs decouple

disconnect is a noun but decouple is not a noun.

Word	Noun	Adjective	Verb	Adverb
disconnect	Yes	No	Yes	No
decouple	No	No	Yes	No

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

Other hyponyms of disconnect include uncouple, detach.

disconnect (noun)	decouple (noun)
an unbridgeable disparity (as from a failure of understanding)

disconnect (verb)	decouple (verb)
make disconnected, disjoin or unfasten	reduce or eliminate the coupling of (one circuit or part to another)
pull the plug of (electrical appliances) and render inoperable	eliminate airborne shock waves from (an explosive)
	regard as unconnected
	disconnect or separate