Longman Dictionary of Contemporary English
thermo-
prefix
EXAMPLES FROM OTHER ENTRIES
▪ a thermostat
The Collaborative International Dictionary
Thermo-
Thermo- \Ther"mo-\ A combining form from Gr. qe`rmh heat, qermo`s hot, warm; as in thermochemistry, thermodynamic.
Douglas Harper's Etymology Dictionary
thermo-
before vowels therm-, word-forming element meaning "hot, heat, temperature," used in scientific and technical words, from comb. form of Greek thermos "hot, warm," therme "heat" (see thermal).
Wiktionary
thermo-
pre. heat