Spanish slang for someone who is borderline stupid, coming from the American slur Mongolic, implying that
the Mongols were not very clever people. This can be used as a neg but is more commonly heard between friends teasing each other, or describing a person who has
half a brain.
The difference between a chonga and a mongi is fashion choices. A chonga will wear hoop earings and fried hair, whereas a mongi could be dressed up or down and also be a chonga at the same time.
Despite it sounding Spanish, it isn't a Spanish word, and I've only heard 2nd gen Latinos say it (cuban americans, etc)