Princeton's WordNet

1. uncommon(adj)

   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. rare, uncommon(adj)

   marked by an uncommon quality; especially superlative or extreme of its kind

   "what is so rare as a day in June"-J.R.Lowell; "a rare skill"; "an uncommon sense of humor"; "she was kind to an uncommon degree"

Kernerman English Learner's Dictionary

1. uncommon(adjective)ʌnˈkɒm ən

   ≠ common

   Attacks by bears are uncommon.; an uncommon sight; It had been uncommonly rainy.; an uncommonly tasty wine

Wiktionary

1. uncommon(Adjective)

   rare; not readily found; unusual

   Bald eagles are an uncommon sighting in this state

2. uncommon(Adjective)

   remarkable; exceptional

   The diamond was of uncommon size

Webster Dictionary

1. Uncommon(adj)

   not common; unusual; infrequent; rare; hence, remarkable; strange; as, an uncommon season; an uncommon degree of cold or heat; uncommon courage

• ongewoon, raarAfrikaans
• غَيْر مألوف، غَيْر شائِعArabic
• необикновенBulgarian
• incomumPortuguese (BR)
• vzácnýCzech
• ungewöhnlichGerman
• ualmindeligDanish
• σπάνιος, ασυνήθιστοςGreek
• raro, poco comúnSpanish
• ebatavaline, haruldaneEstonian
• نادرFarsi
• epätavallinenFinnish
• rareFrench
• לא רָגִיל, לא שָׁכִיחַHebrew
• असामान्यHindi
• rijedak, neobičanCroatian
• ritkaHungarian
• langkaIndonesian
• sjaldgæfur, óvenjulegurIcelandic
• raroItalian
• 珍らしいJapanese
• (보기) 드문Korean
• retas, neįprastasLithuanian
• rets; neparastsLatvian
• tdk biasaMalay
• zeldzaamDutch
• uvanligNorwegian
• niezwykły, rzadkiPolish
• نادرPersian
• كله كله، كله نا كله: لږ مو ندونى (نادر): غير معمولPashto
• raroPortuguese
• neobişnuitRomanian
• редкийRussian
• vzácny, nezvyčajnýSlovak
• redekSlovenian
• neuobičajenSerbian
• ovanligSwedish
• ที่พบได้น้อยThai
• ender, alışılmamışTurkish
• 罕見的，不尋常的Chinese (Trad.)
• незвичний, рідкіснийUkrainian
• نادر، غير معموليUrdu
• bất thường, hiếm thấyVietnamese
• 罕见的，不寻常的Chinese (Simp.)