El Ni·ño (nēnyō)
A climatic event occurring every two to seven years, characterized by warming of surface waters and reduced upwelling of cold, nutrient-rich water off the western coast of South America, causing die-offs of plankton and fish and influencing jet stream winds, altering storm tracks and affecting the climate over much of the world.
[American Spanish (originally used by fisherman in Ecuador and Peru as a name for the warm ocean current typically appearing around Christmastime in El Niño years), from Spanish, the Christ child : el, the (from Latin ille; see al-1 in the Appendix of Indo-European roots) + niño, child (from Old Spanish ninno, from Vulgar Latin *nīnnus).]
(click for a larger image)El Niño
top: normal water temperatures, with warm water concentrated in the western tropical Pacific
bottom: El Niño conditions, with warm water extending from the western tropical Pacific to the eastern Pacific
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2016 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.
American Heritage Dictionary Products
The American Heritage Dictionary, 5th Edition
The American Heritage Dictionary of Idioms
The American Heritage Roget's Thesaurus
Curious George's Dictionary
The American Heritage Children's Dictionary
The American Heritage Dictionary of Indo-European Roots
The American Heritage Student Grammar Dictionary
The American Heritage Desk Dictionary + Thesaurus
The American Heritage Science Dictionary
The American Heritage Dictionary of Business Terms
The American Heritage Student Dictionary
The American Heritage Essential Student Thesaurus