stylet

sty·let

1. A slender, pointed instrument or weapon, such as a stiletto.
2. a. A surgical probe.
   b. A fine wire that is run through a catheter, cannula, or hollow needle to keep it stiff or clear of debris.
3. Zoology A small, stiff, needlelike organ or appendage, such as the feeding organ of a tardigrade.

Origin: French, from Italian stiletto, stiletto; see stiletto .