"Parasocial" is the Cambridge Dictionary's Word of the Year, defined as a relationship felt by someone between themselves and a famous person they do not know.
Its examples include the parasocial interest displayed by fans when singer Taylor Swift and American footballer Travis Kelce announced their engagement.
The term dates back to 1956, when American sociologists observed TV viewers engaging in "para-social" relationships with on-screen personalities.
Chief editor Colin McIntosh said it had recently been used to describe "a type of relationship, between a person and a non-person, for example a celebrity".
"It was originally coined as an academic word and was confined to the academic sphere for quite a long time," he added.
"It's only fairly recently that it's made a shift into popular language and it's one of those words that have been influenced by social media."
Other examples given by the dictionary included Lily Allen's breakup album West End Girl, which leaned into a parasocial interest in her love life, and the emergence of parasocial relationships with AI bots, which saw people treat them as a confidant, friend or romantic partner.
The confessional nature of podcast hosts have been said to replace real friends and to catalyse parasocial relationships.
The dictionary saw a surge in people looking up the word after the Youtube star IShowSpeed blocked an obsessive fan as his "number 1 parasocial".
The word was first coined by University of Chicago sociologists Donald Horton and Richard Wohl, who observed television viewers engaged in "para-social" relationships with on-screen personalities, resembling those they formed with "real" family and friends.
They noted how the rapidly expanding medium of television brought the faces of actors directly into viewers' homes, making them fixtures in people's lives.
Senior editor Jessica Rundell said: "We're not here to judge what's a good word, what's a bad word and whether it's valid - it's more if it stands the test of time and if people are using it all over place."
New entrants to the Cambridge Dictionary included skibidi, delulu and tradwife.
