From The Collaborative International Dictionary of English v.0.48 [gcide]:
Once \Once\ (w[u^]ns), adv. [OE. ones, anes, an adverbial form
fr. one, on, an, one. See One-, -Wards.]
1. For one time; by limitation to the number one; not twice
nor any number of times more than one.
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Ye shall . . . go round about the city once. --Josh.
vi. 3.
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Trees that bear mast are fruitful but once in two
years. --Bacon.
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2. At some one period of time; -- used indefinitely.
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My soul had once some foolish fondness for thee.
--Addison.
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That court which we shall once govern. --Bp. Hall.
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3. At any one time; -- often nearly equivalent to ever, if
ever, or whenever; as, once kindled, it may not be
quenched.
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Wilt thou not be made clean? When shall it once be?
--Jer. xiii.
27.
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To be once in doubt
Is once to be resolved. --Shak.
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Note: Once is used as a noun when preceded by this or that;
as, this once, that once. It is also sometimes used
elliptically, like an adjective, for once-existing.
"The once province of Britain." --J. N. Pomeroy.
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At once.
(a) At the same point of time; immediately; without delay.
"Stand not upon the order of your going, but go at
once." --Shak. "I . . . withdrew at once and
altogether." --Jeffrey.
(b) At one and the same time; simultaneously; in one body;
as, they all moved at once.
Once and again, once and once more; repeatedly. "A dove
sent forth once and again, to spy." --Milton.
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