MEGA-SQUARED is a mathematical term that refers to the number one million multiplied by itself, or 1, 000, 000 x 1, 000, 000. This is also known as a tera, which is a unit of measurement equal to one trillion. MEGA-SQUARED is often used to describe large numbers, such as the population of a city or the amount of money in a bank account. It can also be used to describe the size of a computer's memory or the amount of data stored on a hard drive.