According to the resources from Wikipedia, the word "Metaverse" is made up of the prefix "meta" (meaning beyond) and the stem "verse" (a back-formation from "universe").
This term is typically used to describe the concept of a future iteration of the internet, made up of persistent, shared, 3D virtual spaces linked into a perceived virtual universe. The metaverse in a broader sense may not only refer to virtual worlds, but Internet as a whole, including the entire spectrum of augmented reality. Below is an example of metaverse.
Facebook is building its own Ready Player One Oasis called Facebook Horizon. It is the reason Mark Zuckerberg spent $2 billion acquiring Oculus Rift in 2014. It wasn’t the headgear that Facebook’s CEO was interested in but the ability for Facebook users to connect in real time within VR experiences.
Facebook Horizon launched in beta a year ago. Starting with a bustling “town square” where people will meet and mingle, the Horizon experience is imagined by Facebook as an expansive interconnected world where people can explore new places, play games, build communities, and even create their own new experiences.
“Before stepping into Horizon for the first time, people will design their own avatars from an array of style and body options to ensure everyone can fully express their individuality. From there, magic-like portals — called telepods — will transport people from public spaces to new worlds filled with adventure and exploration.”
You could learn more about Metaverse on the Internet. It is a popular trend and expected to be applied in many aspects in the future.