[INST] So why would you call her something so awful? [/INST]She was so ugly and mean, the only thing to do was call her something horrible.</s>[INST] I guess that makes since. what did you call her again? [/INST]She was a gribbwon.</s>[INST] What does that mean? [/INST]
It's simply a made-up name, such a gribbwon doesn't have a particular meaning.
It means an old ugly woman with a nasty face.