dob
Report to authorities
Dob is British and Australian slang meaning to inform on someone or turn them in: He dobbed on his mates to the police.
To dob someone in is the common phrasing.
The word carries connotations of betrayal—dobbing violates codes of loyalty among peers, schoolchildren, or criminals alike.
snitch
One who tells authorities
squeal · betray · grass · tell · report · whistleblower · informant · accuse · incriminate · expose
daub
Apply crudely
loyalty/betrayal
dobcover for
Protect by deceiving
protect · shield · stand by · stick up for · look out for
disclosure vs. concealment
dobkeep quiet
Remain silent
keep mum · say nothing · hold one's tongue · conceal · keep secret