Catching two cards in a row that you need for a hand is called catching (or needing) runner-runner. An example of this is having three cards to a flush on the flop - you need to hit runner-runner cards of the same suit in order to make your flush.
two cards in a row, usually describing the turn and the river. Used when a losing hand draws out on a better hand against very bad odds. For example, Ad-2d on a board of 3d-Ks-Qh-Td-6d has hit runner-runner diamonds to fill the nut flush.
any two cards dealt in succession that make a (usually improbable) larger hand than the one being drawn to. Example: a player holding the 4â™¥ 5 â™ , looking at the flop of 3â™£ 6â™¥ 10â™¥ might be hoping to see a 2 or a 7 to make a straight. He would, however, make runner-runner flush if the turn and river came J
A hand that is made by drawing two required cards one after another. In holdâ€™em, if Paul has A-K and the flop is T-7-2 then he will get a runner-runner straight if the turn is a Q and the river is a J.