WRONG:

REEKING HAVOC

RIGHT:

WREAKING HAVOC

“Reeking” means “smelling strongly,” so that can’t be right. The phrase simply means “working great destruction.” “Havoc” has always referred to general destruction in English, but one very old phrase incorporating the word was “cry havoc,” which meant to give an army the signal for pillage. To “play havoc with” means the same thing as to “wreak havoc." Avoid as well the mistaken “wreck havoc."

List of errors