Definition - thriving at low temperatures
Cryophilic is a word most often found used in technical contexts. The word comes from the combining forms of cryo- (“cold”) and -philic (“having an affinity for”), and entered the language in the early 20th century. It is typically used to describe bacteria, but may possibly also be used in a figurative manner, to describe your roommate who insists on sleeping with the windows open all winter.
Bacteria are grouped according to their growth temperature: (1) Cryophilic, those able to grow at low temperature with an optimum at 18-20° C.; (2) Mesophilic, which find their optimum at 20-40° C.; and (3) Thermophilic, or heat-loving, which have an optimum at 50-60° C.
— Willem Rudolfs, Principles of sewage treatment, 1941