The Collaborative International Dictionary of English v.0.48:

Cannula \Can"nu*la\, n. [L. cannula a small tube of dim. of
   canna a reed, tube.] (Surg.)
   A small tube of metal, wood, or India rubber, used for
   various purposes, esp. for injecting or withdrawing fluids.
   It is usually associated with a trocar. [Written also
   canula.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Canula \Can"u*la\, n., Canular \Can"u*lar\, a., Canulated
\Can"u*la`ted\, a.
   See Cannula, Cannular, and Cannulated.
   [1913 Webster]