Elmao is the pronunciation of the acronym LMAO which is commonly used today in messaging. LMAO stands for "Laughing My Ass Off". Opposed to WTF, when reading the acronym, one doesn't read it as the actual phrase but as the letters as if they were a word using a latino accent.ELMAO!
Person A: *Text message* OMG this is so funny
Person B: *answering message* Yeah LMAO
Person A: "ELMAO!"