The exact origins of frowsy are perhaps lost in an old, frowsy book somewhere, but some etymologists have speculated that frowsy (also spelled frowzy) shares a common ancestor with the younger, chiefly British, word frowsty, a synonym of frowsy in both its senses. That ancestor could be the Old French word frouste, meaning "ruinous" or "decayed," or the now-obsolete English word frough or frow, meaning "brittle" or "fragile." An early print example of frowsy can be found in Thomas Otway's 1681 comedy The Souldier's Fortune, wherein the character Beau refers to another character as "a frouzy Fellmonger."