What is the meaning of 「ぞんぞん」?

Question

In the following exercise, I'm asked to choose between 「どんどん」,「だんだん」 or 「ぞんぞん」to complete the sentence:

遠慮【えんりょ】しないで、____ 食【た】べてください。 Do not hesitate, eat ____ (adverb) please.

I think that neither どんどん (rapidly, steadily) nor だんだん (gradually) fit well in this sentence, do they? Therefore, I think that the correct choice is ぞんぞん. However, I can't find a proper definition for ぞんぞん in English. I found an article where they talk about ぞんぞん, tried to read it but the required level is way too high for me that I couldn't.

To sum up,

1. What does ぞんぞん mean?
2. Is ぞんぞん the right answer of the exercise?

Answer 1

1. I don't know what ぞんぞん means. (I'm from Kansai, by the way.)
   (In the article you found, they say ぞんぞんする means ぞくぞくする in 土佐 dialect.)

2. The correct answer is どんどん. どんどん can mean not only "rapidly" "steadily" but also "one after another" "do...more (and more)" "do...a lot" "keep on doing" "continuously" etc.

   どんどん食べてください。 "Eat a lot." "Eat more."