What particular one or ones: Which of these is yours? The one or ones previously mentioned or implied, specifically: Used as a relative pronoun in a clause that provides additional information about the antecedent: my house, which is small and old. Used as a relative pronoun preceded by that or a preposition in a clause that defines or restricts the antecedent: that which he needed; the subject on which she spoke. Used instead of that as a relative pronoun in a clause that defines or restricts the antecedent: The movie which was shown later was better. Any of the things, events, or people designated or implied; whichever: Choose which you like best. A thing or circumstance that: He left early, which was wise. What particular one or ones of a number of things or people: Which part of town do you mean? Any one or any number of; whichever: Use which door you please. Being the one or ones previously mentioned or implied: It started to rain, at which point we ran.