hands
Open-ended straight draw
Also: OESD, open-ender, up-and-down straight draw
Four consecutive cards where a card at either end completes a straight, giving eight outs. Combined with a flush draw it becomes a 'combo draw' with up to fifteen outs.
Example. Holding 10-9 on a J-8-3 flop, any queen or seven gives a straight.
An open-ender hits about 32% of the time by the river. Its strength depends on whether it draws to the nuts: 6-5 on 7-8-9 makes only the low end of the straight (the 'idiot end'), while J-10 on 7-8-9 makes the nut straight.