JTA — What does the “alt-right” movement have in common with millennial slang words such as “smackdown,” “slay” and “man bun?”

Turns out they are all among the more than 300 words or terms added to Dictionary.com.

The online dictionary, which announced the additions on Thursday, defines alt-right as “a political movement originating on social media and online forums, composed of a segment of conservatives who support extreme right-wing ideologies, including white nationalism and anti-Semitism (often used attributively).”

It lists the word as having been coined in 2010 by Richard Spencer, a prominent white nationalist, and as being a shortened version of the words “alternative” and “right.”

Spencer, a vocal supporter of President Donald Trump, has used a Nazi term — “Lügenpresse,” or lying press — to describe the mainstream media, and suggested that the media have been critical of Trump in order to protect Jewish interests.

Alt-right leader Richard Spencer in College Station, Texas, December 6, 2016. (AP Photo/David J. Phillip)

Alt-right leader Richard Spencer in College Station, Texas, December 6, 2016. (AP Photo/David J. Phillip)

Other politics-related words and phrases added to Dictionary.com include Black Lives Matter, an activist movement protesting violence and racism against African-Americans; burkini, the full-coverage Islamic bathing suit that was at the center of a controversial ban in France, and clicktivism, the use of social media to express support for various causes.

Dictionary.com isn’t the only word reference tool that lists alt-right. The phrase was on the Oxford Dictionary’s shortlist for top words in 2016, although ultimately “post-truth” was declared the international word of the year.