Mystic's board
I believe the answer is:
ouija
'mystic's board' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ouija that I've seen before include "- Board may be used in a seance" , "Board able to answer questions?" , "Type of board used in seances" , "Board sometimes used at seances" , "This board is used by spiritualists and seances" .)