U+25C0 · emoji since 2010
The reverse button points left to rewind or go back. It means replay, previous, and returning to what came before.
It marks rewinds and second looks, the simple control for taking it back a step.
In texting, ◀️ does not carry a widely used hidden or slang meaning, so you can usually take it at face value. People send it just as it looks, to add a little visual touch or set the mood of a message. Only a handful of emoji have a separate texting code, and ◀️ is not really one of them.
Its official Unicode name is the Reverse Button emoji. In everyday chat most people just call it the reverse button emoji or describe what it shows. Copy and paste it from the button at the top of this page.
The ◀️ leads off a short phrase, and the rest of the words are written in cipher, every letter disguised as another emoji. Tap decipher to reveal the whole line.
Or make your own cipher in the translator.