So you think you know what the definition of 'it' happens to be? It's rather complicated, in fact, a lot of scrolling and reading took place on my part to
come up with this. So, without further babble, 

it: 

The neuter pronoun of the third person, corresponding to the masculine pronoun he and the feminine she, and having the same plural (they, their or
theirs, them). 

Note: The possessive form 'its' is modern, being rarely found in the writings of Shakespeare and Milton, and not at all in the original King James's version of the Bible. During the transition from the regular 'his' to the anomalous 'its', it was to some extent employed in the possessive without the case ending. In Dryden's time 'its' had become quite established as the regular form. 

Usage: It is used, 

1. As a substance for any noun of the neuter gender; as, "Here is the book, take it home." 

2. As a demonstrative, especially at the beginning of a sentence, pointing to that which is about to be stated, named, or mentioned, or referring to that
which apparent or well known; as, "I saw it was John." 

3. As an indefinite nominative for a impersonal verb; as, "It snows," and, "It rains." 

4. As a substitute for such general terms as, the state of affairs, the condition of things, and the like; as, "How is it with the sick man?" 

5. As an indefinite object after some intransitive verbs, or after a substantive used humorously as a verb; as, "To hoof it (i.e., to walk)." 

Isn't IT great that a simple, tiny, two letter word such as IT has such a long and confusing definition? Who would have thought that IT could possibly mean so many different things? IT'S a conspiracy, I tell you, simply our way of keeping foreigners from speaking more than broken English! I'm just glad English was my first language, otherwise I know I'd be lost with IT. Anyway, whatever the reason for IT possessing such a long and big-word-using definition, there ya go. IT'S confusing, is IT not? ^_^V 

Next time I'll find an interesting thing to babble on and on about. But when it gets to be nearly four in the morning I seem to find things like this
fascinating. ^_^' So, I apologize (though if you know me you know I don't mean it ^_-) to those who think this boring, though why would you read it to this point if that was the case? Anyway, if you have an archaic or really niftu (Yes, niftu, look it up  ^_-) word you would like for me to delve into and discover its meaning, I shall, oh I shall. Oh joy, oh rapture! Erm... I'm done. ^_^