A vibrating element of a transducer which radiates sound waves.

1. The part of an antenna or transmission line that radiates electromagnetic waves either directly into space or against a reflector for focusing or directing.

2. A body that emits radiant energy.

Any of numerous devices, units, or surfaces that emit heat, mainly by radiation, to objects in the space in which they are installed.

1. In general, a body which emits particles or radiation in any form.

2. A body placed in a beam of ionizing radiation which, as a result, emits radiation of another kind.