antenna

Short definition from Wiktionary

Noun

1. 1
   An appendage used for sensing on the head of an insect, crab, or other animal.
2. 2
   An apparatus to receive or transmit electromagnetic waves and convert respectively to or from an electrical signal.
3. 3
   The faculty of intuitive astuteness.
4. 4
   A fragment of an oligosaccharide
5. 5
   The spar to which a lateen sail is attached, which is then hoisted up the mast.