From The Collaborative International Dictionary of English v.0.48:
Engineer \En`gi*neer"\, n. [OE. enginer: cf. OF. engignier, F.
ing['e]nieur. See Engine, n.]
1. A person skilled in the principles and practice of any
branch of engineering; as, a civil engineer; an electronic
engineer; a chemical engineer. See under Engineering, n.
[1913 Webster +PJC]
2. One who manages as engine, particularly a steam engine; an
engine driver.
[1913 Webster]
3. One who carries through an enterprise by skillful or
artful contrivance; an efficient manager. [Colloq.]
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Civil engineer, a person skilled in the science of civil
engineering.
Military engineer, one who executes engineering works of a
military nature. See under Engineering.
[1913 Webster]