D defs.my
Entry 1 sense Webster, 1913

Transmitter

/trăn-smĭt'-ẽr/ · Trans·mit·ter · IPA /trænsmˈɪtər/
01 n. One who, or that which, transmits; specifically, that portion of a telegraphic or telephonic instrument by means of which a message is sent…
  1. 1.
    One who, or that which, transmits; specifically, that portion of a telegraphic or telephonic instrument by means of which a message is sent; -- opposed to receiver.