thermometer

Etymology

Borrowed from French thermomètre; equivalent to thermo- + -meter.

noun

1. An apparatus used to measure temperature.
   Towards the following morning, the thermometer fell to 5°; and at daylight, there was not an atom of water to be seen in any direction. 1835, John Ross, James Clark Ross, Narrative of a Second Voyage in Search of a North-west Passage …, Volume 1, pages 284–5
   The brothers had thrust the thermometer between two circuit boards in order to look for hot spots inside m zero. The thermometer’s dial was marked “Beef Rare—Ham—Beef Med—Pork.” “You want to keep the machine below ‘Pork,’” Gregory remarked. March 2 1992, Richard Preston, “The Mountains of Pi”, in The New Yorker