The story
Blend of pen + Benjamin, by analogy with Benjamin > Ben (short form). Popularized by YouTuber and livestreamer Fulcrum around late 2022, although isolated uses exist earlier.
Etymology from Wiktionary, CC BY-SA 4.0.
penjamin
Today it means: A dab pen (a battery-powered pen-shaped device that allows the user to inhale THC vapor). Full definition →