megaphone Meaning, Definition & Usage

  1. noun a cone-shaped acoustic device held to the mouth to intensify and direct the human voice

WordNet

Meg"a*phone noun
Etymology
Mega- + Gr. voice.
Definitions
  1. A device to magnify sound, or direct it in a given direction in a greater volume, as a very large funnel used as an ear trumpet or as a speaking trumpet.

Webster 1913