What does La Nina mean?

• La Nina means Little Girl in Spanish. La Nina is also sometimes called El Viejo that means anti-El Nino (simply a cold event). La Nina has the opposite effect of El Nino. 
• La Niña is caused by a build-up of cooler-than-normal waters in the eastern tropical Pacific. During La Nina events, trade winds are even stronger than usual, pushing more warm water toward Asia.
• The eastern and central parts of the tropical Pacific become even colder, while the west is warmer and experiences more rainfall.

Further Reading:

• Tropical Cyclones
• Temperate Cyclones