To *enthusiastically* agree with something that was said. Makes more sense in texting or online chatting conversations because it uses two "S"s as opposed to "yes" which uses only one "S." A simple "yes" can sometimes be taken as a stock response from someone who is not actually interested in the conversation.
Brandon: I contend that country music brainwashes our youth. Beth: Yess! I enthusiastically affirm this statement.
by bethythepirate December 29, 2009
Word used when something impressive, amazing or crap happens. Also used as an affirmative.
Yess! Au au! Indoid! I did quite quite kick Aaron Chan's ass today! What a snass!
by Andric Leong September 24, 2003