planchette

 
Pronunciation: /plɑːnˈʃɛt/

noun

  • a small board supported on castors, typically heart-shaped and fitted with a vertical pencil, used for automatic writing and in seances: the planchette jerked and skittered to the upper left-hand corner of the paper

Origin:

mid 19th century: from French, literally 'small plank', diminutive of planche