An acronym for "Cold Bed Syndrome".
This is the singles' disorder, where one cannot go to sleep unless someone is there next to them.
Cold Bed Syndrome is most common during the first few months of new-found singledom, but is also common among those who have been single for extended periods of time; especially when said single person has many friends who are in relationships.
The contrary to this would be HBS, or "Hot Bed Syndrome", which is most common among those who are in unhappy relationships and would rather lose sleep than to sleep next to their counterpart.
I've had a horrible case of CBS ever since me and the girlfriend broke up.