parole vs unloosen

parole is a noun but unloosen is not a noun.

Word	Noun	Adjective	Verb	Adverb
parole	Yes	No	Yes	No
unloosen	No	No	Yes	No

As verbs, unloosen is a hypernym of parole; that is, unloosen is a word with a broader meaning than parole:

Other hypernyms of parole include free, liberate, loose, release, unloose.

parole (noun)	unloosen (noun)
(law) a conditional release from imprisonment that entitles the person to serve the remainder of the sentence outside the prison as long as the terms of release are complied with
a promise
a secret word or phrase known only to a restricted group

parole (verb)	unloosen (verb)
release a criminal from detention and place him on parole	loosen the ties of
	grant freedom to; free from confinement