1. An apparatus for reproducing sound, especially that of the voice, at a great distance, by means of electricity; consisting, like the electric telegraph, of transmitting and receiving instruments connected by a line or wire which conveys the electric current.
2. An instrument that converts voice and other sound signals into a form that can be transmitted to remote locations and that receives and reconverts waves into sound signals.

A telephone from which connections may be automatically completed without the aid of an exchange operator by revolving a dial marked with numbers and letters into positions corresponding to the units of the desired telephone number.

1. Making obscene telephone calls for sexual pleasure is known as telephone scatologia and is theorized as a form of exhibitionism.
2. A paraphilia involving unsolicited calls to another person, who is non-consenting, in order to express erotic or obscene language, or to phantasize that such thoughts are being expressed.

Paraphilia (in Greek para, παρά, "beside" + -philia, φιλία, "friendship", having the extended meaning of "love") is a biomedical term characterized by sexual arousal to objects, situations, or individuals that are not part of normal stimulation and which may cause distress or serious problems for the paraphiliac or the people associated with him or her.

Sometimes scatalogia and coprohilia are used interchangeably, although the current preference is to limit scatalogia to the paraphilia, as here defined, and to use coprophilia for involuntary utterances of obscene language.