In the movie, wide shut partly refers to the willful denial (OP’s definition above) of the sinister NWO, and of the sexual deviance of seemingly normal people such as the costume shop owner, the Japanese businessmen, Bill’s wife Alice, and even Bill himself in the context of being a doctor. Wide shut also has the double meaning of sleepwalking through a dreamworld. The movie is based on the 1926 novella Traumnovelle (Dream Story) by Arthur Schnitzler. There are parallels within the movie between things in the waking world and in the dream world. An example are the two parties: Ziegler’s holiday party at the beginning, and the orgy ritual at the mansion. Maybe they’re the same party, and one is just a dream version of the other.