1640s, "feeler or horn of an insect," from L. antenna "sail yard," the long yard that sticks up on some sails, of unknown origin, perhaps from PIE base *temp- "to stretch, extend." In this sense, it is a loan-transl. of Gk. keraiai "horns" (of insects). Modern use in radio, etc., for "aerial wire" is from 1902.
One of a pair of long, slender, segmented appendages on the heads of insects, centipedes, millipedes, and crustaceans. Most antennae are organs of touch, but some are sensitive to odors and other stimuli.
A metallic device for sending or receiving electromagnetic waves, such as radio waves. Some antennas can send waves in or receive waves from all directions; others are designed to work only in a range of directions.