But many of his fans have chosen a different nickname for her.
The word is often shouted from the audience as Trump attacks her, murmured in pre-rally conversations and typed on Twitter. It appears on a popular button sold by vendors at many rallies: "Life's a bitch, don't vote for one." And, most prominently, it is on those white T-shirts, created by the Ohio-based Street Talk Tees and sold at nearly all of Trump's rallies.
In an interview last month, Trump said he was unaware that his fans were using the word.
"They're what? They're calling her what?" Trump said, as the word was repeated to him a second time. "I have not heard that. I don't like that. But I have not heard that. I would not be happy if I heard it."
To many supporters of Clinton - poised to become the nation's first female presidential nominee - the word is a loaded and offensive one that clearly indicates sexism. The commonplace use of the term among Trump boosters also doesn't seem helpful to their candidate, who has dismal popularity ratings among women. Most of the shirts are bought and worn by younger men, although plenty of women purchase them, too.
But many Trump supporters spotted wearing the shirts at rallies over the past six weeks don't think the term is that bad.
"Everybody has gotten too sensitive with terminology," said Amanda Michael, 27, who attended Trump's Greensboro rally with her husband, who wore one of the shirts. "Everybody's just so sensitive now. Trump supporters just go out and they just say how they feel. . . . I'm not offended by it. I mean, it just is what it is. It's just a feel-good American-type thing. We are not over-analyzing every little thing that we say or do."
At a rally in Charleston, W.Va., last month, Matthew Chapa attended with a group of friends and bought one of the shirts.
"I just really don't like her, and I thought it was a funny shirt," said Chapa, 19, a freshman marketing major at Marshall University in West Virginia. "I'm in a fraternity, so the guys will get a nice kick out of it when it's hanging in our fraternity house."
Chapa, who grew up in Houston, said his dislike of Clinton has nothing to do with her being a woman - he's really upset about the attack on Benghazi, which he believes she could have prevented but did not.
"The Benghazi thing makes me sick talking about it," he said as he bought a hot dog before the rally started.
Cousins Dustin White and Matthew Gent live in rural West Virginia and were at the same rally. Although both preferred Sen. Rand Paul, R-Ky., as a presidential candidate, their top reasons for liking Trump are that he is not Clinton and that he is not a Democrat. Gent bought one of the shirts.
"I couldn't resist. I said: 'That's too funny not to buy,' " said Gent, 22, who works at a manufacturing plant. "I mean, people pick on both sides - that's kind of how politics works. It's better to not get mad at it, really. It's all in good fun at the end of the day."
His cousin agreed that it was funny, but that he also didn't like it. Then again, he said, he also didn't like many of President Obama's jokes at the White House correspondents' dinner.
"If we're at a point where the man that has already been elected can stand in front of many serious people from the media, celebrities and other politicians and throw jokes, then I think we are at the point where we can sell shirts that say b---- on them," said White, 22, who works for a water company. "Sadly, I disagree with it. But that's where we stand now."
Ariel Kohane, a 45-year-old from New York City who works for the Republican Leadership Initiative, bought a variation of the shirt made by a different vendor at a rally in Rhode Island and wore it to a GOP fundraiser in New Jersey last month. He said it is an eye-catching conversation starter, especially when walkingon the Upper West Side.
"I'm just trying to be funny and get attention and trying to get people to approach me and talk to me about it, and once they do that, then I can talk to them about Trump," Kohane said. "I definitely get more positive reactions from men than women, but among the Republican women, among the Trump women, they actually love this shirt. I get a lot of high-fives and hugs."
Street Talk Tees is a company based in Aurora, Ohio, that sells mostly shirts featuring the names of colleges, cities and sports teams. Along with obscenities. The company's website includes this disclaimer: "All designs are created just to allow our customers to expres how they feel. FIRST AMENDMENT RULES!"
A team of four or five men in a navy passenger van with Ohio plates has been traveling from rally to rally selling the shirts. They said sales have been strong, although sometimes parents with young children will reprimand them for the foul language while anti-Trump protesters will pepper them with questions.
"It's because I'm black," said Clinton Sanders, 28, one of the salesmen on the all-black team that sticks out in the sea of white faces at Trump rallies. "They want to know who I'm voting for, and I tell them: 'That's confidential.' And they ask me why I'm doing this, and I say: 'I mean, it's work.' "
Sanders said the idea for the shirt came up while a bunch of men were sitting around talking. The front of the shirt features images of Clinton and Lewinsky with the wording: "Hillary sucks but not like Monica."
"It's funny," Sanders said.
William Redwine, a 29-year-old truck driver who lives outside of Greensboro, bought one of the shirts at the Tuesday night rally here after seeing the design online.
"I've been wanting one," said Redwine, a former Democrat who said he became a Republican when Obama was running for office. "It's kind of funny. . . . I'm not politically correct on a lot of things anyway. . . . There are better words to describe Hillary, but - why not?"
Redwine said he thinks that Trump will stabilize the job market, which has been difficult for him in recent years, and that he doesn't like Clinton because of Benghazi, donations she and her husband accepted for their foundation and conspiracy theories about her connections to the Islamic State terrorists.
"It may be true, it may not," he said. "The dots kind of connect."
Another T-shirt buyer on Tuesday night was Travis Beasley, 36, who lives in Greensboro and works an assortment of jobs.
"It's politically incorrect," Beasley said of the shirt. "She's crooked - I think I was calling her crooked before I heard him say it. He took the words right out of my mouth. You can just tell by looking at her, you know? You can just tell by the way she acts. You know how sometimes you just get gut feelings about things?"
A discussion of the b-word and Clinton often leads to Trump supporters saying that their attacks on her have nothing to do with her being a woman. But Feather - the mother of six wearing the "TRUMP THAT B----!" shirt in Greensboro on Tuesday night - said the country would suffer with a woman in the White House.
"There are too many countries who demean their women that I think if we have a woman in office, it's really going to hurt our country more than anything, because they have no respect for women," Feather said as her two young daughters listened. "And then I think our attacks in our country and our issues in our country are going to become even greater, because those countries are not going to have that respect for us. And we're already starting to lose it. And I don't think we need a woman to make us lose it even more."
