意外|いがいigai[0]heiban (flat)

1. na-adjective, adverb (with と), noununexpected; surprising
   意外いがいな結果けっかが発表はっぴょうされた。↗

   Unexpected results were announced.

• Synonym思いがけないおもいがけないNeutralA native adjective for things you never thought of, good or bad alike, as in 「思いがけない出会い」; 「意外」 puts more weight on surprise at a gap from expectations.
• Synonym予想外よそうがいNeutralFor things beyond prediction, as in 「予想外の結果」; stresses a prediction falling through and is fairly objective, while 「意外」 carries a feeling of surprise.
• Synonym不意ふいNeutralFor taking someone by surprise, as in 「不意を突く」「不意の来客」; stresses being caught off guard, while 「意外」 stresses being beyond expectation.
• Synonym思いもよらないおもいもよらないNeutralA set phrase for what you could not even imagine, as in 「思いもよらない展開」; stronger than 「意外」.
• Synonym思わぬおもわぬNeutralA pre-noun word used only attributively, for good or bad things alike, as in 「思わぬ事故」「思わぬ収穫」; 「意外」 can also serve as a predicate or adverb.
• SynonymひょんなCasualA colloquial pre-noun word for chance or odd happenings, mostly in fixed phrases like 「ひょんなことから」; 「意外」 has wider uses.
• Synonym予期しないよきしないWrittenFor things not anticipated in advance, as in 「予期しないエラー」; leans written and technical, as in documentation; in everyday speech say 「意外」.
• Synonym存外ぞんがいWrittenAn adverb meaning 'contrary to expectation', with an old-fashioned ring, as in 「存外うまくいった」「存外難しい」; in everyday speech use 「意外と」.
• Related唐突とうとつNeutralFor words, actions or developments that feel abrupt and lack buildup, as in 「唐突な質問」「唐突な展開」; 「意外」 stresses the gap from expectations.
• Related突然とつぜんNeutralFor things happening suddenly, as in 「突然雨が降る」; stresses the absence of warning signs, while 「意外」 stresses difference from what was expected.
• RelatedにわかNeutralFor suddenness, as in 「にわか雨」, and also for bandwagon fans, as in 「にわかファン」; 「意外」 has no sense of suddenness.
• Related出し抜けだしぬけNeutralFor doing something abruptly, catching someone off guard, as in 「出し抜けに尋ねる」; stresses the lack of warning, while 「意外」 stresses being beyond expectation.
• Related驚くべきおどろくべきWrittenFor astonishing things, as in 「驚くべき発見」; strong in degree and leaning written/formal; 「意外」 does not necessarily imply amazement.
• Antonym当然とうぜんNeutralAntonym: for what is natural and obvious to anyone, as in 「当然の結果」; the opposite of 「意外」, which is beyond expectation.
• Antonym予想内NeutralAntonym: for things within expectations; often paired with 「予想外」; the opposite of 「意外」, which lies outside prediction.

Use 「意外」 when something differs from what you expected and you feel surprise. For results that objectively go beyond a prediction, 「予想外」 fits; when you need an attributive, 「思わぬ」 or 「思いがけない」 works; and when something happens with no warning at all, 「突然」 or 「不意」 is the natural pick.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 以前いぜんに考かんがえていたことと異ことなる様さま。案あんに相違そういし驚おどろきを呼よぶさま。