1.Definition: deviating widely from a norm of physical or mental ability; used especially of children below normal in intelligence

"Special educational provisions for exceptional children"

2.Definition: far beyond what is usual in magnitude or degree

"An exceptional memory"

Related Adjective(s):exceeding, olympian, prodigious, surpassing

3.Definition: surpassing what is common or usual or expected

"Exceptional kindness"

Related Adjective(s):especial, particular, special