antenna n.

1640s, "feeler or horn of an insect or other arthropod," from Latin antenna, antemna "sail yard," the long yard that sticks up on some sails, which is of unknown origin, perhaps from PIE root *temp- "to stretch, extend." In the entomological sense, it is a loan-translation of Aristotle's Greek keraiai "horns" (of insects). Modern use in radio, etc., for "aerial wire" is from 1902. Adjectival forms are antennal (1815), antennary (1833), antennular (1853).