The world has changed so much that we need whole new words and that's happening, though it's hard to keep up. Much trickier is the slide of meanings of words, which has always happened, but not always consciously and not so significantly. At focus here is Trump and his use of lies.
They aren't quite lies, since a lie is something you know about but refuse to acknowledge honestly. Trump has said frankly that when he was in an argument with someone, that person quoted a fact and Trump had no idea whether it was "true" so he just said, "You're wrong." He's on tape saying, "I didn't know, but I just said, You're wrong." Probably he didn't even know what the person was talking about. His life experience is limited, he doesn't read, and he doesn't listen to his advisors, though they are not stellar at understanding either.
The media, with their own definition of lying, is keeping track of things Trump has said that could not be proven accurate or even relevant. The list is hundreds long. At one brief time between yellow journalism and the whistleblower culture, the newspaper was how you figured out the truth. Now you have to go to Snopes.com and hope they're keeping up.
There are a number of dimensions to what Truth is supposed to mean.
1. The actual/factual in the concrete sensory world at a knowable time.
2. Scientific hypotheses which have been proven or nearly so, but are vulnerable to change if better actual/factuals come along.
3. Legal hypotheses which are convincing enough for a jury to believe them.
4, Literary statements that are relevant and believable in the context of the invented story, but maybe not actual/factual -- not even the identity of the author.
5. Things you told your mother to avoid punishment.
6. Things you exaggerated to sound more important and informed.
7. Being drunk and not remembering what you claimed, but realizing it might not be strictly true.
Lately, philosophers and neuro-researchers have been telling us that our brains would never be able to take in everything that is actual/factual outside our skins. There are detailed accounts of how the coded sensations of the vibrating and thumping world get into us and are winnowed to sense by various elements of the gray goo we call "brain." It expects whatever it already knows, and can reject anything too different. It has a tendency to see what it wants and hopes for, rather than the brutal "truth." These phenomena are meant to enhance our chance for survival and in most cases, they do.
But now science tells us that there is far more to the actual/factual than we can ever grasp. Sometimes with machines we can see wave-lengths that won't translate, colors that have no name, music unperceived, temperatures that would kill us anyway. Likewise, if your language has no word for something, no way to say how it works, it's as good as nonexistent. We are limited and temporary.
Institutionalized religion discovered that it could impose words and theories on raw experience and that one of those experiences is holiness, sacredness, which are inexpressible. We can only experience them or point to them. But in the process of forming profit-demanding institutions with big shots and hierarchies and ceremonies of belonging and patternmaking transitions through life, they began to insist on what they called Truth. Not the factual/actual, but the mysterious and miraculous -- virgin birth, surviving fire, three-in-one people -- things to make your jaw drop, and then to defend as absolutely true. For a while it was all so powerful that the Pope was the ultimate Emperor of the Western World and ordered the kings around.
When science became powerful and persuasive in itself, religion was pushed aside. First as a privileged category, and then as just old-fashioned. By the time of the various Enlightenments -- which were conversions to scientific views -- God and the other fanciful ideas about what floats in the sky were all gone, like balloons that had broken their strings and floated off. So now we are left in an enormous space where it's hard to know what to do.
Just beyond the demand to believe in the impossible that religion can impose, is the world of hallucinations. People claim that Martians sucked them into flying saucers, did unbelievable things to them and set them back on earth to tell others. In general, few believe anything they say, even with rolling eyes and frothing mouths, maybe mysterious burns or other afflictions.
But move back to the "real" world where people form groups that share theories about the world that are very different from the world the rest of us know. Some make a "flight to fantasy" that gives them the world they want, not the one they know. We are told that Trump doesn't drink or smoke, but we don't know what pills he takes and he has had some pretty zany doctors. Probably those are not so much about the fantasy world he inhabits as are the late night movies from decades ago, very patterned and very focused on macho bravado. He watches them late at night, all alone in his bathrobe, scarfing fast food. It's impossible to guess how much he has made the dictators from those times into the contents of his own ego.
When we hate something as much as we had to in order to build up a go-for-broke hatred of the WWII Nazis, they become a symbol of evil power -- Lucifer in the face of Jesus. Hannah Arendt and her idea about the banality of small minded people who somehow get hold of the levers of oppression are entirely invisible to some stigma-driven white boy who can't get "laid" because he has no friendly relationship with anyone at all, but fancies it's because of some stigmatized Other who pushes him aside. High school bad boys love rousing the teacher with swastikas on their notebooks.
The biggest lie concerning Trump is that he won the election. He didn't even "game" the system. Trump is a sucker being played by people far smarter and more delusion-free than him or any of his family. To our great regret. We are not under any illusions about this tragedy. We just failed to cry out , LIAR!!!