from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A microprocessor that performs specialized functions that the central processing unit cannot perform or cannot perform as well and as quickly.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An additional microprocessor used to supplement the functionality of the central processing unit, performing tasks such as floating-point arithmetic (floating-point unit) or graphics calculations (graphics processing unit).
co- + processor (Wiktionary)