资料来源 : Webster's Revised Unabridged Dictionary (1913)

Polyoptron \Pol`y*op"tron\, Polyoptrum \Pol`y*op"trum\, n. [NL.,
   from Gr. poly`s many + ? seen.] (Opt.)
   A glass through which objects appear multiplied, but
   diminished in size. [R.]