"The Psychic," on the whole an uneven experiment in terror, had as unheralded an opening as any movie in Washington.Audiences who took potluck on it, however, were probably agreeably surprised by some genuinely clever touches and reflectively sustained shivers.

According to the minimal advertising material available, "The Psychic" was directed by someone named Lucio Fulci, who transcends his overdramatic mannerisms to reveal a talent for orchestrating pictorial suspense. Fulci hits his stride in the last reel or so, when Jennifer O'Neill, evidently lingering in Italy after "The Innocent" and cast as the clairvoyant heroine, is stalked from one old dark premises to another by the killer whose past and future crimes she has envisioned.

Although Fulci plants intriguing clues to the showdown-a shattered wall mirror, a wooden floor lamp with a huge red shade, a yellow-papered cigarette smoldering in a blue ash-tray, a hint of entombment borrowed from Poe's "Cask of Amontillado"-much of the early exposition requires patience. The sound has the sepulchral quality of Italian post-dubbing. One must also put up with repetitive visual hokum, particularly shots boring in for a look at O'Neill's all-seeing eyes.

But once the heroine embarks unwittingly on her final rendezvous with the murderer-clairvoyance conveniently fails her at this juncture to make a spine-tingling conclusion possible-Fulci demonstrates a masterful command of timing, mood and seductively menacing images. He seems to turn the corner during a passage that recalls Martin Balsam's ill-fated walk up the staircase in "Psycho." In this case O'Neill, summoned to a murder house by a possible informant, begins mounting a wide, shadowy staircase and halts at the sight of blood slowly drip, drip, dripping onto the steps from the floor above. When she looks up, the sequence is off and running for perhaps 20 minutes of wittily elaborated hide-and-seek.

Like Dario Argento, the talented but excessive director of horror films like "Suspiria" and "The Bird With the Crystal Plumage," the obscure Fulci seems to have more stuff than he often needs. Still, it's more amusing and rewarding to play along with the excesses of enthusiasm in a Fulci than to wait for a laborious tease, like John Carpenter of the grossly overrated "Halloween," to get his scare-show off the dime.

One could imagine many other actresses supplying a more entertaining performance as a threatened psychic than O'Neill does. Fulci uses her beautiful but usually impassive face as a decorative object in compositions where darkness and threatening emblems appear to be closing in on its luminous surface.

The little detail of the wristwatch given the heroine by a friend is essential. The timepiece proves one of the more delightful props ever exploited in a movie thriller. It plays a critical role on two occasions in the closing minutes, the second cueing a stunning freeze-frame fade-out. CAPTION: Picture, Jennifer O'Neill