The term 'base of a number system' can be summarized as the RADIX, which is a five-letter word. The RADIX is the base of a positional numeral system, which is a system that assigns numerical values to symbols or characters. It is also known as the base of a number system, and it is the number of unique digits, including zero, used to represent numbers in a positional numeral system. The RADIX is an important concept in mathematics and computer science, as it is used to determine the size of a number system.