ちくる More of a slang term- to tell a teacher that Jimmy smokes weed. To tell Dad that Michiko has a 30 year old boyfriend.KID
(みっこく) Snitch on a crime- used in newspapers or police reports.
いつける(いいつける) Kind of a childish word – someone who betrays a secret without knowing they’re doing anything wrong. “Daddy! The lady you called fat is at the door!”