Opposite words for wily:
artless, forthright, unpretentious, public, impressionable, outspoken, undesigning, unforced, unconcealed, honest, guileless, trustful, ingenuous, unaffected, innocent, unstudied, candid, natural, unvarnished, frank, unpretending, obvious, trusting, simpleminded, real, unworldly, plainspoken, patent, unsophisticated, childlike, aboveboard, direct, open, plain, sincere, straightforward, simple.
Usage samples:
  1. 100." " That is too much," was the wily astrologer's reply.
    "Tales of Bengal", S. B. Banerjea.
  2. The idea of winter work did not appeal to the wily Sing, but as it was " work" or " get out," he relented.
    "The Spoilers of the Valley", Robert Watson.
  3. The Prince of Wales said:- " Mr. Hamond, Ladies, and Gentlemen,- I can assure you that no present which has been offered for our acceptance has been received by us with more pleasure than the one which you have given us to- day-- a model of the wily animal that we are all to fond of following.
    "Speeches and Addresses of H. R. H. the Prince of Wales: 1863-1888", Edward VII.
  4. Suppose, thought I, some wily legacy hunter should dispatch an agent to Africa and catch us in our lie?
    "The Satyricon, Complete", Petronius Arbiter.