FYI, I couldn't remember the term so I went to [mathworld://Permutation.html] (Permutation.html). At the bottom are links to "Complete Permutation" and to "Derangement" (clicking the first simply gives a page that points to the second). I've used similar methods to find technical terms for mathematical concepts before; mathematical concepts often have names that are not distinctive so searching for them even when you know them can be problematic. The high degree of cross-linking at MathWorld is one of my favorite features of the site.