Letter bank

A letter bank is a word puzzle related to the anagram, in which all the letters of one word, called the bank, can be reused as many times as needed, with a minimum of once each, to build a new word or phrase. By convention the bank word itself contains no repeated letters. In one classic example, IMPS serves as a bank for MISSISSIPPI, since its four letters multiply out to spell the longer word; in another, SPROUT serves as a bank for SUPPORT OUR TROOPS. The puzzle type was coined by Will Shortz, who created the first published example, BLUME expanding to BUMBLEBEE, in his 1979 book Brain Games. Shortz introduced letter banks to the National Puzzlers' League as a contest puzzle in 1980, and by 1981 the letter bank had been announced as an official puzzle type in the league's magazine The Enigma. Letter banks are also said to underlie the word game Alpha Blitz, though the Wikipedia article notes that particular claim is uncited.