Complex instruction set computer
A complex instruction set computer (CISC ) is a computer architecture in which single instructions can execute several low-level operations (such as a load from memory, an arithmetic operation, and a memory store) or are capable of multi-step operations or addressing modes within single instructions. The term was retroactively coined in contrast to reduced instruction set computer (RISC) and has therefore become something of an umbrella term for everything that is not RISC, where some of the most common differentiating factors of a RISC architecture are uniform instruction length, and strictly separate memory access instructions.
Source: Wikipedia — Complex instruction set computer (CC BY-SA 4.0)