Other forms: thermometers
A thermometer is the small tool that measures how hot your body is. Take his temperature, a digital thermometer, the thermometer read thirty-eight.
Where you measure changes the number: under the arm reads lower than in the mouth, and in the ear lower still, so the reading means nothing without knowing the method. Mercury ones are banned in most countries now. The Greek means heat measure.
1nounthermometerAn instrument that measures temperature.
“The nurse put a thermometer under my tongue to check for a fever.”
thermometer is an instrument.
French thermometre is Greek therme, heat, plus metron, a measure.
Proto-Indo-European
*gʷʰer-
French
thermomètre
English, today
thermometer
French thermomètre; equivalent to thermo- + -meter.
Etymology from Wiktionary, CC BY-SA