n. See indicator, 1 .n. One who or that which transmits.n. Specifically— In telegraphy, the sending or despatching instrument, especially that under the automatic system, in which a paper strip with perforations representing the Morse or a similar alphabet is passed rapidly through an instrument called an automatic transmitter, in which contacts are made by metallic points wherever a perforation occurs, and are prevented where the paper is unpierced.n. In telephony, the microphonic or other apparatus, together with the funnel for receiving the voice and converging the waves of sound upon the thin iron diaphragm. See telephone.