\Se"ta\, n.; pl. {Set[ae]}. [L. seta, saeta, a bristle.]
1. (Biol.) Any slender, more or less rigid, bristlelike organ
   or part; as the hairs of a caterpillar, the slender spines
   of a crustacean, the hairlike processes of a protozoan,
   the bristles or stiff hairs on the leaves of some plants,
   or the pedicel of the capsule of a moss.

2. (Zo["o]l.)
   (a) One of the movable chitinous spines or hooks of an
       annelid. They usually arise in clusters from muscular
       capsules, and are used in locomotion and for defense.
       They are very diverse in form.
   (b) One of the spinelike feathers at the base of the bill
       of certain birds.