\Once\, adv. [OE. ones, anes, an adverbial form fr. one,
on, an, one. See {One-}, {-Wards}.]
1. By limitation to the number one; for one time; 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.