(1):

(n.) A small poniard; a stiletto.

(2):

(n.) An instrument for examining wounds and fistulas, and for passing setons, and the like; a probe, - called also specillum.

(3):

(n.) Any small, more or less rigid, bristlelike organ; as, the caudal stylets of certain insects; the ventral stylets of certain Infusoria.

(4):

(n.) A stiff wire, inserted in catheters or other tubular instruments to maintain their shape and prevent clogging.