be a double-edged sword/weapon

(redirected from weapon)
Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Encyclopedia, Wikipedia.

be a double-edged ˈsword/ˈweapon

be something that has both advantages and disadvantages: This new ‘miracle diet’ is a double-edged sword — it’ll make you lose weight fast but you may have some unpleasant side effects.
See also: sword