catheter

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A hollow flexible tube for insertion into a body cavity, duct, or vessel to allow the passage of fluids or distend a passageway. Its uses include the drainage of urine from the bladder through the urethra or insertion through a blood vessel into the heart for diagnostic purposes.

from The Century Dictionary.

• noun In surgery: A tubular instrument introduced through the urethra into the bladder, to draw off the urine when its discharge is arrested by disease or accident. ⟨b) A tube for introduction into other canals: as, a Eustachian catheter.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Med.) The name of various instruments for passing along mucous canals, esp. applied to a tubular instrument to be introduced into the bladder through the urethra to draw off the urine.
• noun See under Eustachian.
• noun one adapted for passing an enlarged prostate.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun medicine A small tube inserted into a body cavity to remove fluid, create an opening, distend a passageway or administer a drug

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a thin flexible tube inserted into the body to permit introduction or withdrawal of fluids or to keep the passageway open