exceptional
adjective
far beyond what is usual in magnitude or degree
“a night of exceeding darkness”
“an exceptional memory”
surpassing what is common or usual or expected
“he paid especial attention to her”
“exceptional kindness”
deviating widely from a norm of physical or mental ability; used especially of children below normal in intelligence
“special educational provisions for exceptional children”
Source: WordNet 3.1, Princeton University