processor (n.)

early 14c., proces, "fact of being carried on" (as in in process), from Old French proces "a journey; continuation, development; legal trial" (13c.) and directly from Latin processus "a going forward, advance, progress," from past-participle stem of procedere "go forward" (see proceed).

Meaning "course or method of action, continuous action or series of actions or events" is from mid-14c.; sense of "continuous and regular series of actions meant to accomplish some result" (the main modern sense) is from 1620s. Meaning "a projection from the main body of something," especially a natural appendage, is from 1570s. Legal sense of "course of action of a suit at law, the whole of the proceedings in any action at law" is attested from early 14c.; hence due process "fair treatment" at law, considered as a right (mid-15c.).

"miniaturized processor capable of serving as the central processing unit of a computer," by 1970, from micro- + processor.

also multi-processor, "computer system with more than one processor," 1961, from multi- "many" + processor.