widow-maker

noun
wid·​ow-mak·​er | \ ˈwi-dō-ˌmā-kər How to pronounce widow-maker (audio) , -də-\
variants: or widow maker or less commonly widowmaker

Definition of widow-maker

: something having the potential to cause sudden loss of life "Our biggest worry is the mines," says Sgt. Darrell McCoy. The Third Platoon has been well trained to handle those widow-makers.— David H. Hackworth : such as
a : a loose limb hanging in or falling from a tree Broken branches that are hung up high in the canopy are called widow makers, for good reason.— Jack Ewing
b : a blockage in a branch of the left coronary artery that commonly causes a fatal heart attack also : the branch of the left coronary artery susceptible to fatal blockage One of my arteries—one known as "the widowmaker"—was almost completely blocked. — Rob Mikulak