The Collaborative International Dictionary of English v.0.48:

Fubby \Fub"by\, Fubsy \Fub"sy\a.
   Plump; chubby; short and stuffy; as a fubsy sofa. [Eng.]
   [1913 Webster]

         A fubsy, good-humored, silly . . . old maid. --Mme.
                                                  D'Arblay.