What does the word 「ようく」mean?

Question

I came across the word in a manga in a situation that a teenage boy is going to explain something to a group of kids. I cannot find the word in online japanese dictionary.

Here is the sentence.

耳{みみ}をかっぽじってようく きくがいい!

Answer 1

「ようく/よーく」 is an exaggerated pronunciation of 「よく」, which is why it is not found in the dictionary.

「ようくきく」＝「良く聞く」