antenna

(noun) an electrical device that sends or receives radio or television signals. Synonyms: aerial, transmitting aerial.

(noun) sensitivity similar to that of a receptor organ. Synonyms: feeler. Example: "He had a special antenna for public relations."

(noun) one of a pair of mobile appendages on the head of e.g. insects and crustaceans; typically sensitive to touch and taste. Synonyms: feeler.