It

Multiple Entries:
  IT    it  

Concise Oxford English Dictionary © 2008 Oxford University Press:
IT/ʌɪˈtiː/

▶abbreviation information technology.

Concise Oxford English Dictionary © 2008 Oxford University Press:
it1

▶pronoun [third person sing.]

• 1 used to refer to a thing previously mentioned or easily identified.

  ■ referring to an animal or child of unspecified sex.

• 2 used to identify a person.

• 3 used in the normal subject position in statements about time, distance, or weather.

• 4 used in the normal subject or object position when a more specific subject or object is given later in the sentence.

• 5 used to emphasize a following part of a sentence.

• 6 the situation or circumstances.

• 7 exactly what is needed or desired.

• 8 informal sexual intercourse or sex appeal.

• 9 (in children's games) the player who has to catch the others.

– phrases
that's it

• 1 that is the main point or difficulty.

• 2 that is enough.

this is it the expected event is about to happen.

– origin OE hit, neut. of he, of Gmc origin.

Concise Oxford English Dictionary © 2008 Oxford University Press:
it2

▶noun Brit. informal, dated Italian vermouth.