A large integer is a number that is greater than or equal to 10 and has more than one digit. It is usually represented by a string of numbers, such as 1234 or 5678. The term 'large integer' is often used in mathematics and computer science to refer to a number that is too large to be represented by a single data type. In crossword puzzles, the term 'large integer' is often used to refer to a number with three or more digits.