An-tĕn'nă, n.

n.; pl. AN-TĔN'NÆ. [Lat. antenna, sail-yard; N. Lat., a feeler, horn of an insect.] (Zool.) 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 the cavity of the ear is situated near the basal joint. In insects, they are vulgarly called horns, and also feelers; but this latter term is more properly applied to the palpi. P. Cyc.

Firefly. a, a, antennæ.