The Collaborative International Dictionary of English v.0.48:

Quat \Quat\, n. [Etymol. uncertain.]
   (a) A pustule. [Obs.]
   (b) An annoying, worthless person. --Shak.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Quat \Quat\, v. t.
   To satiate; to satisfy. [Prov. Eng.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

quat
    n 1: the leaves of the shrub Catha edulis which are chewed like
         tobacco or used to make tea; has the effect of a euphoric
         stimulant; "in Yemen kat is used daily by 85% of adults"
         [syn: kat, khat, qat, quat, cat, Arabian tea,
         African tea]