The story
The originator of the term is unclear, but it was popularized in a TikTok video posted on September 13, 2022 by Pennsylvania State University student Bradley Kraut: "Absolute academic weapon. Academic weapon." The video showed Kraut in the front row of a university lecture hall with the caption "ACADEMIC WEAPON. FIRST ROW 700 PERSON LECTURE 🤝". This started a TikTok trend of users calling themselves "academic weapons".
Etymology from Wiktionary, CC BY-SA 4.0.