A sword (glave de la mort, the sword of Sir Bevis of Southampton), a generic name for a sword. (See Sword.)
“Had I been accompanied with my Toledo or Morglay.” —Every Woman in her Humour
“Carrying their morglays in their hands.” —Beaumont and Fletcher: Honest Man.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894