I gaslight, you gaslight, he/she/it gaslights. What can this mean? Isn't gaslight some sort of compound noun rather than a verb? But it turns out that gaslight is indeed a verb, one with an interesting history and, moreover, a troublesome relevance to the present.

In 1938, British playwright Patrick Hamilton's work, "Gas Light," was produced in London, and ran for six months. Then it was adapted into a 1940 movie, titled "Gaslight," directed by Thorold Dickinson and starring Anton Walbrook and Diana Wynyard. Four years later, it debuted as an MGM film, featuring Charles Boyer and Ingrid Bergman, with a budget that was an order-of-magnitude larger, and comparably less fidelity to the original play. (As part of the contract, MGM insisted on destroying all pre-existing copies of the 1940 film ... at which, fortunately, the mega-studio was unsuccessful.)

But what is " ," and what does it have to do with the year 2018?

In the story, a wealthy, psychologically "delicate" woman (Bella Mallen) has married a suave, debonair, controlling and decidedly creepy continental European (Paul Mallen) and purchased a multistory London apartment where, decades before, a rich old lady had been murdered and the place ransacked; she was known to have had some extremely valuable rubies. No one had been willing to live in the apartment until its current occupants. Soon it is apparent that Bella is having a hard time: she repeatedly misplaces items, is blamed - by her husband - for taking things when she claims innocence, seems to imagine events that aren't real, and increasingly comes to doubt her own sanity.

It also becomes clear that she isn't crazy after all, but is being craftily manipulated by the nefarious Paul Mallen, who wants to have her "committed" because she accidentally encountered evidence that, unknown to her, could be used against him. The story is set in 1880 London, and in those Victorian times, a husband could have his wife committed simply on his say-so (#MeToo didn't exist.)

Paul regularly prowls about the attic, searching, we discover, for those rubies which he - the murderer - hadn't been able to find when he committed the . As he searches, he turns on the attic gas lights (explaining the movie's title at last), which causes the lights in the rest of the house to dim and flicker; after all, this is 1880, before electricity. Poor belabored Bella notices this, but others - including her well-meaning maid-servant - attribute it to yet another flight of her over- mind.

Eventually, all is set to rights, thanks to the intervention of a retired Scotland Yard detective, who - among other things - confirms the reality of Bella's perception and the of homicidal, perfidious Paul. The film's major contribution to popular culture, as well as to the psychological literature, has been to introduce the verb "gaslight," meaning to induce someone to question their sanity and grasp of reality by malevolently manipulating his or her perceptions.

In the film - especially the 1940 original, which, despite its over-acting and comparatively poor production values, is far superior to the 1944 remake - Paul Mallen is frightening in his malignance, , lack of , and overall creepiness. But he isn't one half as scary, or creepy, as the current occupant of the White House.

I'll make the assumption that most readers are sufficiently well informed that they don't need a recitation of the continuing slurry of deceptions, misrepresentations, and outright lies that have emanated from and continue to disfigure the current Chief Executive and his Administration. Moreover, when caught in these lies, Trump has unfailingly blamed the truth-tellers and doubled-down on his own mendacity, with a self-righteous insistence that makes Paul Mallen look like the mythically Honest Abe Lincoln, or George "I cannot tell a lie" Washington.

I doubt that the current chief executive, unlike the fictional Mr. Mallen, is consciously gaslighting the country, in the sense of deliberately trying to drive us insane; as many have commented, he may actually believe his prevarications, in at least some cases. But the effect of his behavior is more important than his intention. Many veteran journalists and seasoned political observers have noted the extent to which the obvious lies, the self-serving, dishonest claims of " ," as well as the unending barrage of positions taken only to be disavowed immediately afterward have been not only confusing but downright disorienting, so much so in fact that the victims are at risk of becoming as unstable as the perpetrator.

In his March 5 column, The New York Times's Charles Blow put it with characteristically accurate acerbity:

"People used to dealing with a sane, logical person who generally doesn’t lie and generally makes sense are left scratching their heads, wondering whether to believe what they have heard, whether to make plans and policies around it. Believing anything [he] says is a recipe for a headache and heartache. The old rules no longer apply. We see the world as through a window — as it is, even if we are a bit removed from the whole of it. But [he] sees it as if in a house of mirrors — everything reflecting some distorted version of him. His reality always seems to return to a kind of narcissism."

At the end of "Gaslight," Paul Mallen gets his comeuppance, and I am not alone in hoping that the current White House occupant gets his, too. Be warned, however: when this happens in the movie, the cinematic sinner goes more than a bit crazy himself - decompensating, as psychiatrists would put it. But the malignant Mr. Mallen didn't have nuclear weapons at his disposal.

David P. Barash is professor of psychology emeritus, University of Washington and author of Through a Glass Brightly: using science to see our species as it really is, forthcoming in 2018 from Oxford University Press.