As Democrats prepare to watch Hillary Clinton take the stage in Philadelphia Thursday evening and accept the Democratic Party’s nomination for the presidency, they will also likely be preparing themselves for four months of hard campaigning and a fight against “Trumpism.”

What is “Trumpism” exactly? It’s a term that has started to gain ground with pundits and commentators to describe Republican nominee Donald Trump’s manners, behavior and way of thinking and conducting himself. It's also a hashtag and trending topic on Twitter that has garnered thousands of tweets.

Writing in The Hill, political science professor David Tabachnick described Trumpism as being linked to the Republican candidate but also a “uniquely American” political trend that stands apart from traditional American conservatism. In Tabachnick’s definition, the term encompasses four characteristics: celebrity, nativism, the outsider phenomenon and populism.

Trump Republican presidential nominee Donald Trump speaks at a campaign rally in Toledo, Ohio, July 27, 2016. Photo: Reuters/Carlo Allegri

“It embodies a particular kind of American populism composed of a mish-mash of overt patriotism, economic nationalism, along with a vague commitment to the middle class and an aggressive but indefinite foreign policy,” Tabachnick wrote. “Like all populism, Trumpism relies on the rhetoric of resentment but is thin on specifics.”

The Washington Post has described Trump’s behavior during the election season as breaking from traditional American politics, including saying whatever comes to mind on social media and rarely backing down — a behavior that has resonated with voters tired of the status quo in Washington, D.C.

“Trumpism is not defined by any set of policies, or an ideology. It is not handcuffed to coherence or consistency, except in its disregard for what its adherents deem to be political correctness,” the Washington Post wrote. “Trumpism is a personality-fueled movement that has proven, against the smart money’s predictions, to be in tune with the frustrations of a significant slice of the electorate.”

Even popular website Urban Dictionary has tried to define the phenomenon describing it as a “belief system that encourages abrasive, pretentious, narcissistic behavior as the way to achieving money, fame and power.”

Clinton is scheduled to take the stage at the convention after 10 p.m. EDT. Her campaign has said her speech will “lay out very clearly the choice that people face.”

“What we need to do as a campaign and what Hillary is going to do tonight and what we’ve done at this convention is make sure people know the facts,” said Clinton campaign manager Robby Mook Thursday, Politico reported. “This is someone who every turn of his life has made more money, become more famous at the expense of working people and folks need to understand that.”

That likely means that Thursday night speeches will take “Trumpism” full on.