(informal) A secondary Instagram account under which one posts privately or anonymously.
On a seemingly regular basis, young White people's overtly racist remarks are moved out of the shadows of their “Finstas” (fake instagram accounts) and into the “public” domain to be judged by all. 2020, Christopher D. DeSante, Candis Watts Smith, The Millennial Generation and the Stagnation of Racial Attitudes in American Politics, page 101:
I'd say the concept of sliding into one's DMs [direct messages] on Instagram is very powerful, especially because finstas allow people to be more open about things. 2021, anonymous student, quoted in Roberta Katz, Sarah Ogilvie, & Jane Shaw, Gen Z, Explained: The Art of Living in a Digital Age, page 74
“My little sister who's in middle school is doing finstas,” Carrie said. 2017, Nancy Jo Sales, American Girls: Social Media and the Secret Lives of Teenagers, page 134: