Wikipedia
Vesre (reversing the order of syllables within a word) is one of the features of Rioplatense Spanish slang. Natives of Argentina and Uruguay use vesre sparingly in colloquial speaking, and never in formal circumstances. Tango lyrics make widespread use of lunfardo and vesre to highlight the intended underworld atmosphere, or for comic relief.
Vesre is mostly from Buenos Aires, and other cities in Argentina have their own customs. Rosario has its " Rosarigasino" method for obfuscating words, and Córdoba has an entirely different set of colloquial conventions. Yet, most Argentines and Uruguayans have been exposed to vesre through tango lyrics or the media.
Even though vesre has spread to other countries, and can be heard in Peru, Chile and Ecuador, Spanish speakers outside the Río de la Plata area are usually less inclined to use it. Popular speech has created some instances; for example, natives of Barranquilla, Colombia often call their city Curramba, in a stylized form of vesre.