Two words of the same length are said to crash with each other if they contain the same letter in the same position; thus, TORUS and SNOUT crash because both have the letter U in the fourth position, but GUFFAW and MAIDEN do not. FIGHT and MIGHT crash in several positions simultaneously.
Eckler, A. Ross
"Pan-Crashing Word Sets,"
Word Ways: Vol. 15
, Article 21.
Available at: http://digitalcommons.butler.edu/wordways/vol15/iss3/21