A triple squeeze is a squeeze against one player, in three suits; a more explicit definition is "three simple squeezes against the same player."
It is often equated with "progressive squeeze" (also termed a "repeating squeeze"), but progressive squeezes are a subset of triple squeezes. A progressive squeeze is a triple squeeze that, depending both on entries and on positional factors, may result in a subsequent, simple, two-suit squeeze that takes place against the opponent who has just been triple squeezed. Confusing the issue is that some triple squeezes can become progressive squeezes through misdefense.