Widow maker is a nickname used to describe a highly stenotic left main coronary artery or proximal left anterior descending (LAD) coronary artery of the heart. This term is used because if the artery gets abruptly and completely occluded it will cause a massive heart attack that will likely lead to a sudden death. The blockage that kills is made u...
• (n.) One who makes widows by destroying husbands.
anything liable to cause death or serious injury of a workman. 
Wid'ow-mak`er noun One who makes widows by destroying husbands. [ R.] Shak. 
a term for the bowsprit (many sailors lost their lives falling off the bowsprit while tending sails).
[Logging] Any loose overhead debris such as limbs or tree tops that may fall at any time. Widow makers are extremely dangerous and present the faller with a continual source of danger. Limb or other loose material dropped or thrown from a tree toward the faller as the tree is felled.