Meaning

noun a United Nations agency to coordinate international health activities and to help governments improve health services

originFrom Middle English who, hwo, huo, wha, hwoa, hwa, from Old English hwā (dative hwām, genitive hwæs), from Proto-West Germanic *hwaʀ, from Proto-Germanic *hwaz, from Proto-Indo-European *kʷos, *kʷís. The sound change /hw/ > /h/ (without a corresponding change in spelling) was due to wh-cluster reduction after an irregular change of /ɑː/ to /oː/ in Middle English (instead of the expected /ɔː/) and…

Etymology from Wiktionary, CC BY-SA 3.0