Pig Latin is a language game of alterations played in English. To form the Pig Latin form of an English word the onset of the first syllable is transposed to the end of the word and an ay is affixed (for example, trash yields ash-tray and plunder yields under-play and computer yields omputer-cay). The purpose of the alteration is to both obfuscate the encoding and to indicate for the intended recipient the encoding as 'Pig Latin'. The reference to Latin is a deliberate misnomer, as it is simply a form of jargon, used only for its English connotations as a 'strange and foreign-sounding language'.
Another version is to take the first letter from the word (unless a vowel) and put it at the end with an added ay. Using the examples above: trash becomes rashtay, and plunder becomes lunderpay.