The Collaborative International Dictionary of English v.0.48:

Potiche \Po`tiche"\, n.; pl. -tiches. [F., fr. pot a pot.]
   (Ceramics)
   A vase with a separate cover, the body usually rounded or
   polygonal in plan with nearly vertical sides, a neck of
   smaller size, and a rounded shoulder.
   [Webster 1913 Suppl.] Potichomania