process (v.1) Look up process at Dictionary.com
1530s, "begin legal action against," from Middle French processer "to prosecute," from proces (see process (n.)). Meaning "prepare by special process" is from 1881, from the noun in English. Of persons, "to register and examine," by 1935. Related: Processed; processing.
process (n.) Look up process at Dictionary.com
early 14c., "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" is from mid-14c.; sense of "continuous series of actions meant to accomplish some result" (the main modern sense) is from 1620s. Legal sense of "course of action of a suit at law" is attested from early 14c.
process (v.2) Look up process at Dictionary.com
"to go in procession," 1814, "A colloquial or humorous back-formation" from procession [OED]. Accent on second syllable.