Dummy

a deaf-and-dumb person; a clumsy, awkward fellow; any one unusually thick-witted.
in three-handed whist the person who holds two hands plays dummy.
a pocket-book. In this word the derivation is obvious, being connected with dumb i.e., that which makes no sound. As a thieves' term for a pocket-book, it is peculiarly applicable, for the contents of pocket-books, bank-notes and papers, make no noise, while the money in a purse may betray its presence by chinking.