Princeton's WordNet

1. unwise(adj)

   showing or resulting from lack of judgment or wisdom

   "an unwise investor is soon impoverished"

2. inexpedient, unwise(adj)

   not appropriate to the purpose

Kernerman English Learner's Dictionary

1. unwise(adjective)ʌnˈwaɪz

   ≠ wise

   The decision was unwise.; It would be unwise to think the troubles will end soon.; He spent his money unwisely.; When used unwisely, the drug can cause great harm.

Wiktionary

1. unwise(Adjective)

   Not wise; defective in wisdom; injudicious; indiscreet; foolish.

   unwise man; unwise kings; unwise measures

Origin: From unwis, from unwis, equivalent to . Cognate with onwijs, unweise, uvis, ovis, óvís.

Webster Dictionary

1. Unwise(adj)

   not wise; defective in wisdom; injudicious; indiscreet; foolish; as, an unwise man; unwise kings; unwise measures

• onwys, domAfrikaans
• غَيْر حَكيمArabic
• глупавBulgarian
• insensatoPortuguese (BR)
• nerozumnýCzech
• unklugGerman
• uklogDanish
• ανόητος, απερίσκεπτοςGreek
• imprudenteSpanish
• rumalEstonian
• احمقانهFarsi
• epäviisasFinnish
• imprudentFrench
• לא נָבוֹןHebrew
• अज्ञानता, मूर्खताHindi
• nerazumanCroatian
• nem okosHungarian
• bodoh, tidak bijaksanaIndonesian
• óviturlegurIcelandic
• imprudenteItalian
• 愚かなJapanese
• 어리석은Korean
• neprotingasLithuanian
• ne visai gudrs; muļķīgsLatvian
• tdk bijakMalay
• onverstandigDutch
• uklok, ufornuftigNorwegian
• niemądryPolish
• imprudentePortuguese
• nechibzuitRomanian
• не(благо)разумныйRussian
• nerozumnýSlovak
• nespametenSlovenian
• nerazumanSerbian
• oklok, oförståndigSwedish
• ไม่ฉลาดThai
• aptalTurkish
• 不智的Chinese (Trad.)
• нерозумний, нерозсудливийUkrainian
• احمقانہ، احمقUrdu
• ngu xuẩnVietnamese
• 愚蠢的Chinese (Simp.)