The term LARGE PART OF AN ATLAS can be solved by the crossword solution ASIA, which is a four letter word. ASIA is the largest continent in the world, covering an area of 44, 579, 000 square kilometers, or 17, 212, 000 square miles. It is home to over 4.5 billion people, making it the most populous continent on Earth. ASIA is also home to some of the world's oldest civilizations, including China, India, and Japan.