What is the origin of the term "widow's peak"?

Search: widows peak

Why: In Beat the Reaper, Magdalena has one.

Answer: Two possibilities:

• As people get older, their hairlines often recede. This makes a widow's peak more prominent - or the appearance of a widow's peak on a person who does not actually have one. A woman with a widow's peak has lived long enough to outlive her husband.
• A 1500s-style mourning cap or Mary Stuart cap features a triangular piece of cloth on the forehead that resembles a widow's peak.
  

Source: WiseGeek

The More You Know: On a man, it's called a widower's peak.