The Collaborative International Dictionary of English v.0.48:
Attorney \At*tor"ney\, n.; pl. Attorneys. [OE. aturneye, OF.
atorn['e], p. p. of atorner: cf. LL. atturnatus, attornatus,
fr. attornare. See Attorn.]
1. A substitute; a proxy; an agent. [Obs.]
And will have no attorney but myself. --Shak.
(a) One who is legally appointed by another to transact
any business for him; an attorney in fact.
(b) A legal agent qualified to act for suitors and
defendants in legal proceedings; an attorney at law.
Note: An attorney is either public or private. A private
attorney, or an attorney in fact, is a person appointed
by another, by a letter or power of attorney, to
transact any business for him out of court; but in a
more extended sense, this class includes any agent
employed in any business, or to do any act in pais, for
another. A public attorney, or attorney at law, is a
practitioner in a court of law, legally qualified to
prosecute and defend actions in such court, on the
retainer of clients. --Bouvier. -- The attorney at law
answers to the procurator of the civilians, to the
solicitor in chancery, and to the proctor in the
ecclesiastical and admiralty courts, and all of these
are comprehended under the more general term lawyer. In
Great Britain and in some states of the United States,
attorneys are distinguished from counselors in that the
business of the former is to carry on the practical and
formal parts of the suit. In many states of the United
States however, no such distinction exists. In England,
since 1873, attorneys at law are by statute called
A power, letter, or warrant, of attorney, a written
authority from one person empowering another to transact
business for him.