英语词源字典 - 在线词源网站

doctor (v.)[doctor 词源字典]: 1590s, "to confer a degree on," from doctor (n.). Meaning "to treat medically" is from 1712; sense of "alter, disguise, falsify" is from 1774. Related: Doctored; doctoring.[doctor etymology, doctor origin, 英语词源]
phony (adj.): also phoney, "not genuine," 1899, perhaps an alteration of fawney "gilt brass ring used by swindlers."
His most successful swindle was selling "painted" or "phony" diamonds. He had a plan of taking cheap stones, and by "doctoring" them make them have a brilliant and high class appearance. His confederates would then take the diamonds to other pawnbrokers and dispose of them. ["The Jewelers Review," New York, April 5, 1899]
The noun meaning "phony person or thing" is attested from 1902.