WordWeb Online

1. Not common or ordinarily encountered; unusually great in amount or remarkable in character or kind
   "uncommon birds"; "frost and floods are uncommon during these months"; "doing an uncommon amount of business"; "an uncommon liking for money"; "he owed his greatest debt to his mother's uncommon character and ability"
    
2. Marked by an uncommon quality; especially superlative or extreme of its kind
   "an uncommon sense of humour"; "she was kind to an uncommon degree";
   - rare

1. To a remarkable degree or extent
   - unusually, remarkably, unco [UK, dialect], notably

See also: commonness, commonplaceness, especial, everydayness, exceptional, extraordinary, particular, rare, red carpet, red-carpet, special, unusual, unwonted

Antonym: common

Encyclopedia: Uncommon