Webster's English Dictionary

it

1. it \(')it, *t\ pn [ME, fr. OE hit - more at HE] 1: that one - used as 
   subject or direct object or indirect object of a v erb or object of a 
   preposition usu. in reference to a lifeless thing {took a quick look at the 
   house and noticed ~ was very old}, a plant {there is a rosebush near the 
   fence and ~ is now blooming}, a person or animal whose sex is unknown or 
   disregarded {don't know who ~ is}, a group of individuals or things, or an 
   abstract entity {beauty is everywhere and ~ is a source of joy}; compare 
   HE, ITS, SHE, THEY 2: - used as subject of a verb that expresses a 
   condition or action with out reference to an agent {~ is raining} 3a: - 
   used as anticipatory subject or object of a verb {~ is nec essary to repeat 
   the whole thing}; often used to shift emphasis to a part of a statement 
   other than the subject {~ was in this city that the treaty was signed} 3b: 
   - used with many verbs as a direct object with little or no meaning  
   {footed ~ back to camp} 4: the general state of affairs or circumstances 
   {how is ~ going>
2. it \'it\ n : the player in a game who performs a function (as trying to 
   catch others  in a game of tag) essential to the nature of the game