The Collaborative International Dictionary
Guiser \Guis"er\ (g[imac]z"[~e]r), n. [From Guise.] A person in disguise; a masker; a mummer. [Obs. or Prov. Eng.]
Douglas Harper's Etymology Dictionary
"masquerader, mummer," late 15c., agent noun from guise.
alt. A person in disguise. n. A person in disguise.
Usage examples of "guiser".
On the perimeter of the figure and moving round it, danced the Old Guiser, William Andersen.
She found that, after the Guiser had acted out his mock decapitation, the Sons danced again and the Betty and Hobby-Horse improvised.
But always the Sons danced again and, at a fixed point, the Guiser rose up as if resurrected.
Would you swear that it was in fact the Guiser who danced the role of Fool?