Meaning of one up

one' up'

Pronunciation: [key]
  1. having gained an advantage in some way that betokens success, esp. over rivals.
  2. leading an opponent by one point or one scoring unit: The home team was one up on the visitors.
  3. one each; tied at a score of one: The score was one up in the ninth inning.
  4. with only one reproduction of a form per sheet or on a given sheet: We must print this job one up.
  5. using one more column of space than of type.

one-up

Pronunciation: (wun'up'), [key]
— -upped, -up•ping.
  1. to get the better of; succeed in being a point, move, step, etc., ahead of (someone): They one-upped the competition.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.