Top definition
YCSI is a commonly used acronym for "you can suck it". Such acronyms are common among today's texting-crazy youth and refers to the act of fellatio. This term can be used by either gender, however, without confusing ramifications.
"Ur mom looks hot, lol"
"YCSI"
by HaterCaid March 17, 2010
Get the mug
Get a ycsi mug for your sister Zora.