From plan + -on with dissimilation.
plavon m (plural plavons) (slang)
- a plan, or particularly a great one
2021 July 2, 1PLIKÉ140 (lyrics and music), “Poison”[1]:C’est nous, on envoiе l’plavon, mais tu vas lâcher un billet- We lay down a plan, but you are down for a ticket