Engine

—A compound machine or mechanical contrivance by which any physical power is applied to produce a given effect. The term engine is more commonly applied to ma ive machines, or to those of great power, or which produce some difficult result. It takes, in composition, other words, designating either the source of power, as steam engine, air engine, caloric engine, or the purpose to which it is applied: as, fire engine, pumping engine, locomotive engine; or some peculiarity of construction, operation, or use: as, single acting or double acting engine, high pre ure or low pre ure engine.