I have checked some other texts of Oliver Twist, and they seem to use the conventional spelling of the word 'parochial'. Dickens did like to spell words the way (he thought) certain characters would pronounce them, but in this case it may well be a typo for 'parochial'. As for the meaning, it's to do with administrative boundaries of a city. A person who is 'parochial' lives within a certain parish (administrative district) of a town or city, and a person who is 'extra-parochial' is from outside it. In other words, he means a local person or an outsider. This difference is significant, because Mr Bumble is the beadle of the parish, and he has responsibility for local charitable institutions such as the workhouse where Oliver Twist lives. Bumble would have some authority over parochial person, but not over an extra-parochial one. By the way, this is where the modern and international meaning of narrow-minded, which Sophia mentions, comes from. However, that is not what the word means in this context. The meaning is the original one, as explained above.

The word is how Mr Bumble pronounces "parochial". You can check the definition and see how it fits the sentence. In a case like this, reading the text aloud would help you when a character has uncommon pronunciation.

porochial is probably a typo for parochial, which means to have a narrow view of the world, or sometimes refers to the parish of a church. In this sentence it means narrow-minded "they had better not！"said Mr. Bumble ,clenching his fist. 'let me see any man 'porochial or extra-porochial, as would presume to do it; and i can tell him that he wouldn't do it a second time " means something like: "They better not!" Mr. Bumble said, clenching his fist. "Show me any one close-minded enough to try to do it. I'll tell him he wouldn't do it twice"

I think it was mispronounced intentionally by the author to show the character's lack of words. The correct spell is parochial. I'm struggling to read the book, too.

Advice for reading something like this... It's a hard book in general. Read slowly and use a dictionary.