nark vs betrayer

nark and betrayer both are nouns.

Word	Noun	Adjective	Verb	Adverb
nark	Yes	No	Yes	No
betrayer	Yes	No	No	No

As nouns, betrayer is a hypernym of nark; that is, betrayer is a word with a broader meaning than nark:

nark: an informer or spy working for the police
betrayer: one who reveals confidential information to the police or other authority

Other hypernyms of nark include blabber, informer, rat, squealer.

nark (noun)	betrayer (noun)
an informer or spy working for the police	a person who says one thing and does another
a lawman concerned with narcotics violations	one who reveals confidential information to the police or other authority

nark (verb)	betrayer (verb)
inform or spy (for the police)
cause annoyance in; disturb, especially by minor irritations