couple vs coupler

couple and coupler both are nouns.

Word	Noun	Adjective	Verb	Adverb
couple	Yes	No	Yes	No
coupler	Yes	No	No	No

couple (noun)	coupler (noun)
a pair who associate with one another	a mechanical device that serves to connect the ends of adjacent objects
a pair of people who live together
(physics) something joined by two equal and opposite forces that act along parallel lines
two items of the same kind
a small indefinite number

couple (verb)	coupler (verb)
engage in sexual intercourse
link together
bring two objects, ideas, or people together
form a pair or pairs