short for "fake instagram". used for ugly selfies, memes, inside jokes, etc. Usually has humorous names as the username, such as a misspelling of users name.
Amelia : lmao that pic ugly af. tag my finsta
Bianca : gotchu fam
short for "real instagram". Usually contains aesthetics, themes, and good quality photos. Known as the "official" instagram of the user.
see also : finsta
Amelia : This picture is gorgeous ! I'll put in on my rinsta.