This book contains important words and terminologies of the core subjects in mechanical engineering such as engineering mechanics, strength of materials, fluid mechanics, thermodynamics, IC engines, heat and mass transfer, refrigeration and air-conditioning, manufacturing processes, theory of machines, industrial engineering and management, electric vehicles, etc. that are explained in a concise and lucid manner. The contents also touch upon some terminologies of basic science subjects. This dictionary is an easy-to-use and a practical resource which will be highly useful for undergraduate and postgraduate students, researchers, and industry professionals in the field of mechanical engineering.