noun: (idiomatic) Something which or someone who takes the lives of men; a lethal hazard that affects mostly men or is specific to a primarily male trade.
noun: (forestry) The detached or broken limb of a tree, a hazard to those walking underneath.
noun: (medicine, informal) The left coronary artery, or its anterior interventricular branch, occlusion of which is likely to cause a fatal heart attack.
