案あんの定じょう

あ

ん

の

じょ

う

Common wordJLPTN2Freq.FrequencyTop 20,000

Meanings

Used when something happens exactly as one predicted, often with a nuance of an undesirable or unfortunate outcome.

案あんの定じょう〈事こと〉になったsure enough, things turned out (as feared)
案あんの定じょう、電でん車しゃは遅おくれることになった。
Sure enough, the train ended up being late.
案あんの定じょう、〜てしまったsure enough, (something bad) ended up happening
案あんの定じょう、彼かれは約やく束そくを忘わすれてしまった。
Sure enough, he ended up forgetting his promise.
案あんの定じょう〈動どう詞し〉as expected, (someone) did (something, usually bad)
案あんの定じょう、彼かの女じょは試し験けんに落おちた。
As expected, she failed the exam.

やはりN4
やはり is a broad 'as expected/after all' that works in both positive and negative contexts, while 案の定 specifically flags that a feared or predicted (often bad) outcome came true.
予よ想そう通どおりN2
予想通り is neutral and simply means 'as predicted' without implying good or bad, while 案の定 usually carries a negative or regretful nuance.
果はたしてN2
果たして is a more literary word that can mean either 'as expected' or 'I wonder if', while 案の定 unambiguously confirms that a prediction came true.
さすがN2
案の定 describes an outcome that unfolded exactly as predicted, often with a negative or ironic edge, whereas さすが praises someone or something for living up to a good reputation.

案あん外がいN3
案外 shares the kanji 案 with 案の定 but means the opposite: 'unexpectedly' or 'contrary to expectations', not 'as expected'.

From 案 (plan, expectation) + possessive の + 定 (certainty, rule). Literally 'as per the plan's certainty', it came to mean 'just as one expected'.