theremin
Concise Oxford English Dictionary © 2008 Oxford University Press:
theremin /ˈθɛrəmɪn/
▶noun an electronic musical instrument in which the tone is generated by two high-frequency oscillators and the pitch controlled by the movement of the performer's hand towards and away from the circuit.
– origin early 20th cent.: named after its Russian inventor Lev Theremin.
'theremin' also found in these Oxford entries:

