A movable, articulated organ of sensation, attached to the heads of insects and Crustacea. There are two in the former, and usually four in the latter. They are used as organs of touch, and in some species of Crustacea the cavity of the ear is situated near the basal joint. In insects, they are popularly called horns, and also feelers. The term in also applied to similar organs on the heads of other arthropods and of annelids.
- Zoology One of the paired, flexible, segmented sensory appendages on the head of an insect, myriapod, or crustacean functioning primarily as an organ of touch.
- Something likened to this sensory appendage, as in function or form: sensitive public relations antennae.
- A metallic apparatus for sending or receiving electromagnetic waves.