The possessive case of who or which. See who, and which, Of whom, belonging to whom; used as an interrogative pronoun, Of which, belonging to which; used as a relative pronoun

interrogative pronoun What person or people; which person or people (used in a direct or indirect question), relative pronoun The person or people that, noun_ A person under discussion; a question of which person, a United Nations agency to coordinate international health activities and to help governments improve health services

A compound relative or indefinite pronoun, standing for any one which, whichever, that which, those which, the ? which, and the like, A relative pronoun, used esp. in referring to an antecedent noun or clause, but sometimes with reference to what is specified or implied in a sentence, or to a following noun or clause (generally involving a reference, however, to something which has preceded). It is used in all numbers and genders, and was formerly used of persons, relative Who; whom; what (of those mentioned or implied), noun_ An occurrence of the word which, A chest, Specifically, a movable wagon-box, determiner_ interrogative What one or ones (of those mentioned or implied), relative the one mentioned, now dialectal Used of people (now generally who, whom or that)