Means 'Obsessive Status Update Disorder'
When someone on Facebook Or another social networking site constantly updates their status 24/7 with stuff that no one really cares about and is just infact annoying.
Ashley is going to Thorpe park
Ashley is at Thorpe park
Ashley is going to ride saw for the 5th time today
Ashley is in the queue for Rush because Saw ride broke down.
Everyone else on Facebook : He has OSUD! This is the type of situation where we need a ''nobody cares'' button.