一而再, 再三

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.

Ye shall . . . go round about the city once. --Josh.
vi. 3.

Trees that bear mast are fruitful but once in two
years. --Bacon.

2. At some one period of time; -- used indefinitely.

My soul had once some foolish fondness for thee.
--Addison.

That court which we shall once govern. --Bp. Hall.

3. At any one time; -- often nearly equivalent to ever, if
ever, or whenever; as, once kindled, it may not be
quenched.

Wilt thou not be made clean? When shall it once be?
--Jer. xiii.
27.

To be once in doubt
Is once to be resolved. --Shak.

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.

{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.