What does Idiot End mean in poker?

In poker, Idiot End is the weak end of a straight. It may look like a made hand, but it often loses to a higher straight.

How does it work?

The problem is that the player has technically made a straight, but did so from the lower end and can easily still be behind. This hand is dangerous precisely because of that misleading sense of completion: the combination is already there, but its real strength is less reliable than it first appears. The term is useful because it reminds players of one simple thing: not every made straight is equally strong, especially when the board also allows a higher one.