: a machine that changes energy (such as heat from burning fuel) into mechanical motion
: the vehicle that pulls a train
: something that is used for a particular purpose
Machine that can convert any of various forms of energy into mechanical power or motion. The steam engines developed during the Industrial Revolution to power stationary machinery were modified in the 19th century to propel locomotives and ships, and were joined later by steam turbines. Internal-combustion engines were developed by Nikolaus Otto and Rudolf Diesel in the late 19th century. Gas turbines and rocket engines came into use in the later 20th century. See also diesel engine, gasoline engine, jet engine, rocket, and rotary engine.
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