Entry 1 sense Webster, 1913 Thermo- · Ther·mo- · IPA /θɜɹ.moʊ-/ 01 A combining form from Gr. qe`rmh heat, qermo`s hot, warm; as in thermochemistry, thermodynamic. 1. A combining form from Gr. qe`rmh heat, qermo`s hot, warm; as in thermochemistry, thermodynamic.