Princeton's WordNet

1. improbable, unlikely(adj)

   not likely to be true or to occur or to have occurred

   "legislation on the question is highly unlikely"; "an improbable event"

2. unlikely(adj)

   has little chance of being the case or coming about

   "an unlikely story"; "an unlikely candidate for reelection"; "a butcher is unlikely to preach vegetarianism"

3. improbable, unbelievable, unconvincing, unlikely(adj)

   having a probability too low to inspire belief

Kernerman English Learner's Dictionary

1. unlikely(adjective)ʌnˈlaɪk li

   without a strong chance of happening or succeeding

   It's unlikely (that) they'll be here before dark.; You're unlikely to get tickets now.

2. unlikelyʌnˈlaɪk li

   not easy to believe

   an unlikely story about the car breaking down

Wiktionary

1. unlikely(Noun)

   Something or somebody considered unlikely.

2. unlikely(Adverb)

   In an improbable manner.

3. unlikely(Adjective)

   Not likely; improbable; not to be reasonably expected; as, an unlikely event; the thing you mention is very unlikely. Not holding out a prospect of success; likely to fail; unpromising; as, unlikely means.

   It's very unlikely that you'll be able to walk perfectly after being in a cast for six months.

Webster Dictionary

1. Unlikely(adj)

   not likely; improbable; not to be reasonably expected; as, an unlikely event; the thing you mention is very unlikely

2. Unlikely(adj)

   not holding out a prospect of success; likely to fail; unpromising; as, unlikely means

3. Unlikely(adj)

   not such as to inspire liking; unattractive; disagreeable

4. Unlikely(adverb)

   in an unlikely manner

• onwaarskynlikAfrikaans
• غَيْر مُحْتَمَلArabic
• невероятенBulgarian
• improvávelPortuguese (BR)
• nepravděpodobnýCzech
• unwahrscheinlichGerman
• usandsynlig; næppeDanish
• απίθανος, αδύνατοςGreek
• improbableSpanish
• ebatõenäolineEstonian
• بعیدFarsi
• epätodennäköinenFinnish
• improbableFrench
• לא מִתקַבֵּל עַל הַדַעַתHebrew
• असंभावितHindi
• slabo vjerojatan, nesiguranCroatian
• nem valószínű, hogy; valószínűtlenHungarian
• mustahilIndonesian
• ólíklegurIcelandic
• improbabileItalian
• ありそうもないJapanese
• 있을 법하지도 않은Korean
• neįtikėtinas, vargu ar galimasLithuanian
• nedomājams; neticams; neiespējamsLatvian
• tdk mungkinMalay
• onwaarschijnlijkDutch
• usannsynlig, lite troligNorwegian
• nieprawdopodobnyPolish
• بعیدPersian
• ناشونې، بې احتمالهPashto
• pouco provávelPortuguese
• improbabil, puţin probabilRomanian
• неправдоподобный; маловероятныйRussian
• nepravdepodobnýSlovak
• malo verjetenSlovenian
• malo verovatanSerbian
• osannolikSwedish
• ที่ไม่น่าจะเกิดขึ้นThai
• olası olmayanTurkish
• 未必的Chinese (Trad.)
• неправдоподібний, малоймовірнийUkrainian
• نا ممکنUrdu
• không chắc xảy ra, không chắc đúngVietnamese
• 未必的Chinese (Simp.)