Definition: The word "subscript" refers to the part that appears in between a letter, number or symbol indicating the subscript size. It can also be used to indicate an exponent, which indicates how many times to multiply a base by itself. For example: - The letter 'a' has a subscript of 2. - The letter 'b' has a subscript of 3. The definition for "subscript" is that it is the part that appears in between a letter, number or symbol indicating the size of the subscript. It can also be used to indicate an exponent, which indicates how many times to multiply a base by itself.