[ 'plɛktrəm ]
■ noun ( plural ~s or plectra -trə ) a thin, flat piece of plastic or tortoiseshell used to pluck the strings of a guitar or similar musical instrument.
↘the corresponding mechanical part which plucks the strings of an instrument such as a harpsichord.
Origin
ME: via L. from Gk plēktron 'something with which to strike', from plēssein 'to strike'.