whistle blower vs whistleblower

whistle blower and whistleblower both are nouns.

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

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

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

Other synonyms of whistle blower include whistle-blower.

whistle blower (noun)	whistleblower (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