the.com/microprocessor

means A single tiny chip that packs an entire computer's core logic — the part that fetches instructions and does the arithmetic and decisions — onto one piece of silicon.

from Built from 'micro-' (Greek mikros, small) plus 'processor,' the computing term for the unit that processes data. Before the early 1970s, a computer's 'brain' (the CPU) was built from many separate chips wired together on circuit boards. The breakthrough was squeezing that whole logic unit onto a single integrated circuit — engineers at companies like Intel, working on calculator chip designs, realized one small chip could be made general-purpose enough to run any program. The word simply names what's new about it: the processor, now microscopic.