It  pron. (poss. Its; pl. They) 1 thing (or occasionally an animal or child) previously named or in question (took a stone and threw it). 2 person in question (who is it? It is i). 3 as the subject of an impersonal verb (it is raining; it is winter; it is two miles to bath). 4 as a substitute for a deferred subject or object (it is silly to talk like that; i take it that you agree). 5 as a substitute for a vague object (brazen it out). 6 as the antecedent to a relative word or clause (it was an owl that i heard). 7 exactly what is needed. 8 extreme limit of achievement. 9 colloq. A sexual intercourse. B sex appeal. 10 (in children's games) player who has to perform a required feat.  that's it colloq. That is: 1 what is required. 2 the difficulty. 3 the end, enough. [old english]