Not too long ago, you wouldn't come across the word "unicorn" very often outside a kindergarten classroom.
But "unicorn" is just one of the numerous words that, thanks to a recent shift in meaning, gets used regularly in 2017 in headlines and on social media.
While most of these words have been around for years, it took this year for them to shoot into the mainstream and shape the way we talk about business, politics, and current events.
Here are six words that took on completely different meanings in 2017:
In the world of finance, Unicorns are extremely rare. Of course, those unicorns are something else entirely -- they're startup companies valued at $1 billion or more.
Venture capitalist Aileen Lee coined the term in 2013, when $1 billion startups were extremely scarce. But four years later, there are more than 200 such companies, including Uber, Hulu, and Warby Parker.
"As their name indicates, unicorns were originally so rare as to be almost mythical," hedge fund manager Jennifer Fan wrote.
"We now have a blessing of unicorns, each one of which has the potential to transform financial and cultural norms."
2017 saw the word "snowflake" gain traction as a pejorative used by conservatives to insult liberals perceived as being overly sensitive.
The term is shorthand for "Generation Snowflake," which in turn originated from the 1996 novel "Fight Club":
"You are not special. You are not a beautiful and unique snowflake. You're the same decaying organic matter as everything else," a line from the book reads.
The new usage of the word became popular enough to shed the "generation" prefix, and becam especially popular among surrogates and supporters of President Donald Trump.
"It became the epithet of choice for right-wingers to fling at anyone who could be accused of being too easily offended, too in need of 'safe spaces,' too fragile," journalist Jessica Goldstein wrote in a ThinkProgress article about the history of the word.
In the wake of Trump's election a year ago, the word "normalize" underwent an abrupt change of meaning among political pundits and activists.
Originally, people used "normalize" in the sense of returning something to a normal state, like relations between two countries.
But after the election, as editors of Merriam-Webster noted, people began using the word in a subtly different way, referring to a change in society's standards to accept ideas that were once considered outside the mainstream.
"The 'normalization of hate,' then, is not the removal of extreme and hateful rhetoric or views to fit the mode of modern discourse, but instead the redefinition of modern discourse to allow those extreme views to be considered normal," Merriam-Webster explained in a blog post about the changing definition.
The words "active shooter" can stop you in your tracks if you hear them on the news or see them in your social media feed.
However, before Mass Shootings were depressingly commonplace, the words "active shooter" signaled something completely different.
As the terminology would suggest, an "active shooter" used to mean someone who actively participated in the recreational sport of shooting," according to Merriam-Webster editor Kory Stamper, who wrote about the word in a Washington Post column this year.
Starting the in the late 1970s, law-enforcement officers began using the term to refer to someone who was in the process of using a gun to commit a crime, and after the Columbine High School shooting in 1999, the term entered common parlance.
With mass shootings in the United States occurring more and more regularly, people have become painfully aware of the new sense of the phrase.
Fake news is practically as old as the news itself, but over the past few years, it has become more and more difficult for people to agree on what it means.
Since Trump's inauguration, the president has increasingly used the term "fake news" to refer to news that portrays him negatively, regardless of the story's accuracy.
The pronoun "they" is no longer relegated to plural status. This year saw the word continue to grow in popularity as a way to refer to a single person who identifies as neither male nor female.
The gender-neutral sense of the word was named Word of the Year in 2015, and since then, a number of newspapers and English experts announced they would expand their terminology beyond just "he" and "she."
This post originally appeared on Business Insider.