Weirdly, I don’t ever remember hearing the word “toon” in that context before, but I instinctively knew what it meant, so I must have learned it (probably from my few remaining WoW-playing friends) and then forgotten all about learning it.
When doing your survey of RPG jargon, make sure to include for each term: 1) a functional definition; 2) a sardonic definition; 3) a ranty definition explaining how each term is totally fucking useless now and we don’t talk about it and if you want to know what it means then go read these 25 closed threads with 500 posts each, any number of which might be digressions or personal attacks or references to out-of-print ashcan editions of indie games.