Fed up, pissed off, disappointed.
Thought by some to have come from a euphemism for 'buggered', it is actually of 14th Century English origin, the original phrase was to be in a "
Brown study", where 'brown' = dark &
sombre, 'study' = a daydreamy state. Meaning has shifted to today's meaning, and the phrase has become "
Browned off".