Definition of "it"
The third-person singular personal pronoun used to refer to an inanimate object, to an inanimate thing with no or unknown sex or gender.
The third-person singular personal pronoun used to refer to an animate entity of unknown gender.
Used to refer to oneself when identifying oneself, often on the phone, but not limited to this situation.
The impersonal pronoun, used without referent as the subject of an impersonal verb or statement. (known as the dummy pronoun or weather it).
The impersonal pronoun, used as a placeholder for a delayed subject, or less commonly, object. (known as the dummy pronoun or, more formally in linguistics, a syntactic expletive).
That which; what.
One who is neither a he nor a she; a creature; a dehumanized being.
The person who chases and try to catch the other players in the playground game of tag.