Definition: backronym

(BACKward acRONYM) A reverse acronym. Instead of turning a multi-word term into letters, such as "central processing unit" into CPU, a given set of letters becomes a multi-word term. For example, TEMPEST was a code name that was turned into "Telecommunications Electronics Material Protected from Emanating Spurious Transmissions." DVD originally meant "digital video disc" but was later changed to "digital versatile disc." See acronym.