who meaning

1. originally, an interrogative pronoun, later, a relative pronoun also; used always substantively, and either as singular or plural. See the Note under What, , 1. As interrogative pronouns, 'who' and 'whom' ask the question: What or which person or persons? 'Who' and 'whom', as relative pronouns (in the sense of 'that'), are properly used of persons (corresponding to 'which', as applied to things), but are sometimes, less properly and now rarely, used of animals, plants, etc. 'Who' and 'whom', as compound relatives, are also used especially of persons, meaning the person that; the persons that; the one that; whosoever

1. (United_Nations_agency) a United Nations agency to coordinate international health activities and to help governments improve health services
Related: WHO, W.H.O.