The word "existential" has been chosen as Dictionary.com's word of the year.
The site said the word had been used more than ever throughout 2019 in relation to politics, climate change and terror attacks.
The research showed that searches for the word spiked after both Democratic presidential contender Bernie Sanders and 16-year-old climate activist Greta Thunberg characterised climate change as an "existential" crisis.
There was another spike when former Vice President Joe Biden, also vying for the Democratic presidential nod, painted President Donald Trump as an "existential threat" to decency.
The word is defined as "of or relating to existence" and "of, relating to, or characteristic of philosophical existentialism; concerned with the nature of human existence as determined by the individual's freely made choices".
John Kelly, senior research editor for the site, said: "In our data, it speaks to this sense of grappling with our survival, both literally and figuratively, that defined so much of the discourse."
"Existential" is also associated with Forky the white plastic spork, who was the breakout star of Toy Story 4.
"Forky underscores how this sense of grappling can also inspire us to ask big questions about who we are, about our purpose," Mr Kelly said.
Oxford Dictionaries picked "climate emergency" as its word of the year, saying that it reflects the "ethos, mood, or preoccupations of the passing year".
Dictionary.com has been picking a word of the year since 2010.
"We started to see existential in the dialogue beginning in January and all the way through the year," said Jennifer Steeves-Kiss, Dictionary.com's chief executive officer.
"This is a consistent theme that we saw in our data, but it also was leveraged across many different important questions of our time."
