twin

Meaning

1. A close friend, used as a term of address with no actual family tie.
2. Someone whose personality or opinions closely match your own.

“You ordered the same thing as me again. Twin.”

Where it came from

The friendly sense of the word comes from African American Vernacular English, where it marked a deep bond between people who are not related. Gen Z and Gen Alpha slang popularized it as a casual greeting and compliment in the early 2020s.