definition of
detector

[1] #1 detector n. [sensor, sensing element] any device that receives a signal or stimulus (as heat or pressure or light or motion etc.) and responds to it in a distinctive manner. wn

[2] #2 detector n. [demodulator] rectifier that extracts modulation from a radio carrier wave. wn

[3] #3 detector n. electronic equipment that detects the presence of radio signals or radioactivity. wn