Define Double Letters Meaning

when a frat guy or sorority girl overdoes their Greek pride by wearing multiple articles of clothing with their Greek letters on them, whether it be a hat and a shirt, a shirt and shorts, open jacket with t-shirt underneath. Considered to be lame and over the top in Greek communities.

Any first or last word you use, add double letters at the end or beginning of the word to assert your dominance

On myspace (mostly) or networking sites, or generally the internet, teens often have what is called "double letter syndrome", this is when they spell every word with a double, triple, or more letters than necessary. Can, often times be extremely confusing and just plain annoying.

Doubling the last letter of a word to make it funnier to read and say. Can also be used to take away the seriousness of a message.
Example: From log to logg, bread to breadd, thick to thicc.