1. Used to refer to that one previously mentioned. Used of a nonhuman entity; an animate being whose sex is unspecified, unknown, or irrelevant; a group of objects or individuals; an action; or an abstraction: polished the table until it shone; couldn't find out who it was; opened the meeting by calling it to order.
2. Used as the subject of an impersonal verb: It is snowing.
3. 1. Used as an anticipatory subject or object: Is it certain that they will win?
   2. Used as an anticipatory subject to emphasize a term that is not itself a subject: It was on Friday that all the snow fell.
4. Used to refer to a general condition or state of affairs: She couldn't stand it.
5. Used to refer to a crucial situation or culmination: This is it—the rivals are finally face to face. That's it! I won't tolerate any more foolishness.
6. Informal Used to refer to something that is the best, the most desirable, or without equal: He thinks he's it. That steak was really it!

1. Games A player, as in tag, who attempts to find or catch the other players.
2. An animal that has been neutered: The cat is an it.

Our Living Language  : "I told Anse it likely won't be no need." This quotation from William Faulkner's As I Lay Dying demonstrates a use of it that occurs in some vernacular varieties of American speech. It is used instead of Standard English there when there functions as a so-called existential—that is, when there indicates the mere existence of something rather than a physical location, as in It was nothing I could do. Existential it is hardly a recent innovation—it appears in Middle English; in Elizabethan English, as in Marlowe's Edward II: "Cousin, it is no dealing with him now"; and in modern American literature as well. Although most British and American varieties no longer have this historical feature, it still occurs in some Southern-based dialects and in African American Vernacular English. Use of existential it may actually be increasing in some places, such as Smith Island, Maryland, a historically isolated community. While older Smith Islanders sometimes use existential it rather than there, younger islanders almost always do. · In some American vernacular dialects, particularly in the South (including the Appalachian and Ozark mountains), speakers may pronounce it as hit in stressed positions, especially at the beginning of a sentence, as in Hit's cold out here! This pronunciation is called a relic dialect feature because it represents the retention of an older English form. In fact, hit is the original form of the third person singular neuter pronoun and thus can be traced to the beginnings of the Old English period (c. 449-1100). Early in the history of English, speakers began to drop the h from hit, particularly in unaccented positions, as in I saw it yesterday. Gradually, h also came to be lost in accented positions, although hit persisted in socially prestigious speech well into the Elizabethan period. Some relatively isolated dialects in Great Britain and the United States have retained h, since linguistic innovations such as the dropping of h are often slow to reach isolated areas. But even in such places, h tends to be retained only in accented words. Thus, we might hear Hit's the one I want side by side with I took it back to the store. Nowadays, hit is fading even in the most isolated dialect communities and occurs primarily among older speakers. · This loss of h reflects a longstanding tendency among speakers of English to omit h's in unaccented words, particularly pronouns, such as 'er and 'im for her and him, as in I told 'er to meet me outside. This kind of h-loss is widespread in casual speech today, even though it is not reflected in spelling. See Note at Smith Island.