One, n.
  1. A single unit; as, one is the base of all numbers.
  2. A symbol representing a unit, as 1, or i.
  3. A single person or thing. “The shining ones.” --Bunyan. “Hence, with your little ones.”
     He will hate the one, and love the other.   --Matt. vi. 24.
     That we may sit, one on thy right hand, and the other on thy left hand, in thy glory.   --Mark x. 37.
  After one, after one fashion; alike. [Obs.] --Chaucer.
  At one, in agreement or concord. See At one, in the Vocab.
  Ever in one, continually; perpetually; always. [Obs.] --Chaucer.
  In one, in union; in a single whole.
  One and one, One by one, singly; one at a time; one after another. “Raising one by one the suppliant crew.” --Dryden.
  one on one contesting an opponent individually; -- in a contest.
  go one on one, to contest one opponent by oneself; -- in a game, esp. basketball.