予想外|よそうがいyosougai

1. no-adjective, na-adjectiveunexpected; unforeseen; strange
   彼かれは予想外よそうがいの結果けっかにまごついた。↗

   He was perplexed at the unexpected result.

• Synonym思いがけないおもいがけないNeutralNeutral adjective for something you simply didn't think of, as in 「思いがけない出会い」 or 「思いがけない知らせ」; 「予想外」 leans more toward differing from prior expectations.
• Synonym意外いがいNeutralThe most common everyday word for 'unexpected'; 「予想外」 puts more weight on going beyond what was expected in advance.
• Synonym不意ふいWrittenWritten/formal prose for something sudden that catches you off guard, as in 「不意を突く」; 「予想外」 is about being contrary to what was expected.
• Synonym心外しんがいWrittenWritten/formal prose for the unexpected that leaves you regretful or annoyed; 「予想外」 itself is neutral.
• Synonym慮外りょがいWrittenWritten/formal prose meaning either unexpected or, in another use, rude and presumptuous; 「予想外」 is neutral.
• Synonym思いもよらないおもいもよらないNeutralFor things so far from your mind you couldn't even imagine them; 「予想外」 is the more objective term.
• Synonym思わぬおもわぬNeutralA pre-noun word only, as in 「思わぬ事故」; 「予想外」 is a noun and can stand on its own.
• SynonymひょんなCasualColloquial for odd, chance occurrences, as in 「ひょんなことから」; 「予想外」 is about defying prior expectations.
• Synonym予期しないよきしないWrittenWritten/formal prose for results that were not anticipated; 「予想外」 is the more concise way to say it.
• Synonym存外ぞんがいWrittenWritten/formal prose for 'unexpectedly, contrary to expectations', often used of a pleasant surprise, as in 「存外おいしい」; 「予想外」 is neutral.
• Related唐突とうとつWrittenWritten/formal prose for something abrupt or brusque; 「予想外」 is about results that differ from what was expected.
• Related突然とつぜんNeutralFocuses on how quickly something happens; 「予想外」 focuses on the mismatch with what was expected.
• RelatedにわかWrittenWritten/formal prose for sudden, impromptu things, as in 「にわか雨」; 「予想外」 is about being contrary to expectations.
• Related出し抜けだしぬけCasualColloquial for something happening out of the blue, without warning; 「予想外」 is about outcomes defying prior expectations.
• Related驚くべきおどろくべきWrittenWritten/formal prose for something astonishing that makes you marvel; 「予想外」 leans toward simply not matching predictions.
• Antonym予想通りよそうどおりNeutralThe direct opposite: things turning out exactly as expected, with no surprises.
• Antonym想定内そうていないWrittenWritten/formal prose for what stays within the scope of prior assumptions; the opposite of 「予想外」.

Use 「予想外」 for what goes beyond what was expected in advance, as in 「予想外の展開」 or 「予想外の質問」. For a plain 'unexpected', reach for 「意外」 or 「思いがけない」; for suddenness, 「突然」 or 「不意」; for 'better than expected', 「存外」. The opposites are 「予想通り」 and 「想定内」.

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

1. 思いの外おもいのほか。意外いがい。