thermodynamics, thermodynamical, thermodynamically 1. The branch of physicochemical science concerned with heat and energy and their conversions one into the other involving mechanical work. 2. The branch science which is concerned with the study of energy and with the relationship of heat transfer and work to other forms of energy. 3. The study o... Found on http://www.wordinfo.info/words/index/info/view_unit/4265/20