he, she, etc. will murder you
(one) will murder (someone)
One will be extremely, belligerently angry with someone (though not with an actual intent to kill them). Mom will murder you if she finds out you broke her antique vase! I swear, I'll murder him if he goes poking his nose in my room again.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
he, she, etc. will ˈmurder you(spoken) used to warn somebody that another person will be very angry with them: Your brother will murder you when he finds out what you’ve done to his car!
Farlex Partner Idioms Dictionary © Farlex 2017