Top definition
a feeling brought on when a current fling's attitude reminds you of an ex-girlfriend.
if your current girlfriend happens to piss you off because of her lack in a display of affection, and this fact reminds you of an ex girlfriend, then she suffers from the "O" syndrome.
by Mark Ray May 07, 2006
Get the mug
Get a the "O" syndrome mug for your friend Yasemin.