Refers to a seed that forces the player to enter a dungeon to gain a progression item and then leave due to the fact that they do not possess the items required to defeat the dungeon, thereby requiring them to come back later. If a player is forced to do this twice, they have now “triple dipped” into that dungeon.
For example, let’s say the player goes into Turtle Rock to look for progression items, which can be advantageous since it contains five items. The player finds the Pegasus Boots on Laser Bridge, but since they haven’t found the Ice Rod which is required to defeat Trinexx the boss of Turtle Rock, they must leave. With the Pegasus Boots, they’re able to check Bonk Rocks, which contains the Ice Rod. So they must travel back to Turtle Rock and defeat Trinexx to gain the crystal at Turtle Rock, and they’ve been forced to Double Dip.