Sadly, I do not know the origins of the word "nobble". But I'm sure you have worked out its meaning - "do something nasty to for whatever purpose". It could mean to capture someone/thing, or remove some opposition, maybe poison a person . . . you get the idea. I of course am using it in terms of the kidnapping sense above. It's quite a generalised word, basically, which can have many applications
The difference between genius and insanity is merely the difference between success and failure.