1. An interrogative pronoun and a relative pronoun; can be either singular or plural.
2. One; anyone.

Acronym for World Health Organization.

The, English rock group, formed 1964, with a hard, aggressive sound, high harmonies, and a propensity for destroying their instruments on stage. Their albums include Tommy 1969, Who’s Next 1971, and Quadrophenia 1973.
Originally a mod band, the Who comprised Pete Townshend (1945– ), guitar and songwriter; Roger Daltrey (1944– ), vocals; John Entwistle (1944– ), bass; and Keith Moon (1947–1978), drums.