squealer
squeal-er
noun
An informal term for a person who secretly informs on others, often to authorities.
"The gang suspected a squealer in their ranks."
noun
An animal or device that produces a high-pitched squealing sound.
"The piglet was a real squealer."
Thesaurus
Synonyms: pig, hog, grunter, Sus scrofa, betrayer, informer, blabber, rat