Initialism of World Health Organization.

plural of who's who

Alternative form of who's who

(countable, sometimes capitalized) A publication containing biographies of well-known or important people. / (countable) A list of notable, famous, or upper-class people.

(interrogative, dialect, African-American Vernacular) whose

A person under discussion; a question of which person.

(interrogative) What person or people; which person or people; asks for the identity of someone; used in a direct or indirect question. / With antecedent as subject.

Misspelling of whose.

Who is. / Who has. / Whom is. / Who (whom) does

Honorific alternative letter-case form of who, sometimes used when referring to God or another important figure who is understood from context.