plectrum

from WordNet (r) 3.0 (2006)

plectrum
    n 1: a small thin device (of metal or plastic or ivory) used to
         pluck a stringed instrument [syn: {pick}, {plectrum},
         {plectron}]

from The Collaborative International Dictionary of English v.0.48

Plectrum \Plec"trum\, n.; pl. L. {Plectra}, E. Plectrums . [L.,
   fr. Gr. ? anything to strike with, fr.? to strike.]
   A small instrument of ivory, wood, metal, or quill, used in
   playing upon the lyre and other stringed instruments.
   [1913 Webster]