vicious circle vs vicious cycle

vicious circle and vicious cycle both are nouns.

Word	Noun	Adjective	Verb	Adverb
vicious circle	Yes	No	No	No
vicious cycle	Yes	No	No	No

As nouns, vicious circle and vicious cycle are synonyms defined as:

vicious circle and vicious cycle: one trouble leads to another that aggravates the first

vicious circle (noun)	vicious cycle (noun)
an argument that assumes that which is to be proved	one trouble leads to another that aggravates the first
one trouble leads to another that aggravates the first