Feeling sick or unhealthy.
I'm feeling a bit under the weather. So, I'm not comin' to office.
by Arun Prakash September 12, 2006
This is the British middle class equivalent of the exclamations 'ill' or 'sick', meaning cool. Being terribly modest and reserved, one doesn't want to overstate things.
Yo brother, that deck is a bit under the weather
by Bob Q. Holness July 30, 2008