Definition of "antenna"

antenna

/ænˈtɛn.ə/

noun
plural antennae or antennas
1. An appendage used for sensing on the head of an insect, crab, or other animal.
  Quotations
  The overall shape of most insect antennae is elongate and cylindrical, although elaborations into plumose, lamellate, or pectinate forms have arisen many times in different insect lineages.
  2006, Timothy Duane Schowalter, Insect Ecology: An Ecosystem Approach, page 22
  He put his fingers over his head like two antennas, crossed his eyes, and waggled his tongue like some kind of insect.In the same work, Brown uses antennae to refer to both aerials and feelers during more technical descriptions.
  2009, Dan Brown, Deception Point, page 24
  The basis of these relationships lies in the olfactory chemoreceptors of insect antennas...
  2010, Craig S. Charron, Daliel J. Cantliffe, "Volatile emissions from plants", Horticultural Reviews, pages 43-72
2. An apparatus to receive or transmit electromagnetic waves and convert respectively to or from an electrical signal.
3. (figurative) The faculty of intuitive astuteness.
  Quotations
  Most nurses believe they are born with an antenna of sorts, which is able to guide them through clinical practice and help them determine what is right and what is not...
  2006, Kelly Pyrek, Forensic Nursing, page 5
  Obama is astute. He approaches things with the help of a sensitive antenna.
  2010, Mary Lou Decostérd, Right Brain/Left Brain President: Barack Obama's Uncommon Leadership Ability, page 106
4. (biochemistry) A fragment of an oligosaccharide
5. (nautical) The spar to which a lateen sail is attached, which is then hoisted up the mast.