To Floss (slang): 1) To show off material things or expensive lifestyle, 2) To do a popular dance move featured on social media 3) To slide a piece of string in between your teeth for cleaning
Paul is talking to his friend Devin during a party
Paul: Jose is flossing on everyone with that outfit today.
Devin: Yeah. The shirt and pants are from Supreme. Super expensive!
Paul: So, how was your weekend?
Devin: I was flossing in my Tesla with the ludicrous mode on.
Paul: Wow, I guess everyone is flossing these days but me!
Two friends at a night club
Cindy: Look at Frankie out on the dance floor! What's he doing?
Kat: Oh, haven't you seen it on social media? They even put it on Fortnite. It's called "The Floss or Flossing," and it's a special dance move.
Cindy: It looks fun and easy!
Jimmy at the Dentist's Office
Dentist: Jimmy, you have 8 cavities!
Jimmy: Really? But I floss my teeth at least once a week.
Dentist: You need to brush and floss your teeth every day in order to avoid getting cavities.
Explanation: "To floss" has several meanings but has recently been used as a slang term for showing off something expensive. In the first example, Jose is showing off his expensive clothes at the party. Later, Devin says that he showed off his Tesla last weekend. In the second example, Frankie is flossing on the dance floor. It is the name of a popular dance move that you can see an example of here.
Finally, the traditional meaning of "floss" is related to cleaning in between the teeth with a string. In the third example, Jimmy has 8 cavities because he doesn't floss his teeth regularly.