What does canula mean?
A canula is a thin, typically flexible tube that is inserted into a vein, body cavity, or duct so that fluids can be introduced or withdrawn. In hospitals it most often refers to the small tube left in a patient's arm after venepuncture, allowing repeated injections or drips without further needle sticks, though nasal versions are also common for delivering supplemental oxygen. The word belongs firmly to formal medical vocabulary: patients encounter it on wards and consent forms rather than in casual conversation, where simpler terms such as "tube" or "drip" prevail. It is a variant spelling of the more widely used "cannula," which carries a double n; both forms derive ultimately from the Latin canna, meaning a reed or cane, reflecting the device's original resemblance to a narrow hollow stalk. For anyone navigating medical settings, knowing the term helps in understanding procedures, equipment lists, and clinical instructions.
nounA variant spelling of cannula: a thin tube inserted into a vein, body cavity, or duct to administer medication, drain fluid, or allow access during medical procedures.
- A slender tube inserted into a vein, body cavity, or duct for administering fluids, draining matter, or gaining surgical access.
- (By extension) any similar narrow tube or sleeve-shaped instrument used in medical or laboratory procedures.
"The nurse threaded the canula gently into the patient's forearm before attaching the intravenous line."
"The anaesthetist inserted the canula into the back of her hand before the operation began."
"Oxygen was delivered through a nasal canula while the patient recovered on the ward."
As a Latin-derived noun, the classical plural is canulae, though the anglicized canulas is increasingly common in everyday clinical writing.
"Several canulae were laid out on the tray, each sized for a different vein."
This little 'reed' has been letting doctors slip into veins since Roman times — its name literally comes from the Latin word for a hollow cane.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of canula
Canula derives directly from the Latin canna, meaning a reed, cane, or hollow tube, via a diminutive form. It entered English as a medical term around the early seventeenth century, when anatomical and surgical texts borrowed freely from Latin. Its cognates include canal, channel, and cane, all tracing back to that same root for a hollow reed. The double-n spelling cannula arose later and has become the dominant modern form.
Related word forms
How canula is actually used
Formal and technical register, used almost exclusively in medical and clinical contexts. The double-n spelling "cannula" now dominates in both British and American medical writing; "canula" persists as a recognized variant but may be considered nonstandard by some style guides.
Easily confused with canula
Cannula (with double n) is the standard spelling in modern medical usage, while canula is an accepted older or British variant of the same word.