clinical thermometer

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

• noun A thermometer used to measure body temperature, especially a small glass thermometer designed with a narrowing above the bulb so that the mercury column stays in position when the instrument is removed from the body.

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

• noun a mercury thermometer designed to measure the temperature of the human body; graduated to cover a range a few degrees on either side of the normal body temperature