whistle-blower vs whistle blower

whistle-blower and whistle blower both are nouns.

Word	Noun	Adjective	Verb	Adverb
whistle-blower	Yes	No	No	No
whistle blower	Yes	No	No	No

As nouns, whistle-blower and whistle blower are synonyms defined as:

whistle-blower and whistle blower: an informant who exposes wrongdoing within an organization in the hope of stopping it

Other synonyms of whistle-blower include whistleblower.

whistle-blower (noun)	whistle blower (noun)
an informant who exposes wrongdoing within an organization in the hope of stopping it	an informant who exposes wrongdoing within an organization in the hope of stopping it