The term KNOX OR DIX can be solved by the crossword solution FORT, which is a four-letter word. A FORT is a defensive structure, typically made of stone or brick, designed to protect a military base or settlement from attack. Forts were used throughout history to protect people and their possessions from enemy forces. The two names Knox and Dix refer to two famous forts in the United States: FORT Knox and FORT Dix. FORT Knox is located in Kentucky and is best known as the site of the United States Bullion Depository, where the country's gold reserves are stored. FORT Dix is located in New Jersey and is a major training center for the United States Army.