Source : Webster's Revised Unabridged Dictionary (1913)

Cryometer \Cry*om"e*ter\, n. [Gr. ? cold, frost + -meter.]
   (Physics)
   A thermometer for the measurement of low temperatures, esp.
   such an instrument containing alcohol or some other liquid of
   a lower freezing point than mercury.

Source : WordNet®

cryometer
     n : a thermometer designed to measure low temperatures