A Slang You Need To Know : “saiaku”

Dropped your phone. Missed your train. Stepped in something on the sidewalk. These moments all call for one word in Japanese: 最悪さいあく! This slang expression is incredibly common in everyday Japanese, and knowing it — along with its close cousin 最低さいてい — will make your Japanese sound genuinely native.

Yuka

Rei, I hear 最悪さいあく all the time but I’m not sure when to use it. Is it always slang?

Rei

最悪さいあく literally means “the worst” but in daily conversation it’s used as a strong expression of frustration — like “this sucks!” or “terrible!” It works alone as an exclamation, or as an adjective: 最悪さいあくな___. You’ll also hear 最低さいてい used the same way, especially about people who behave badly.

At a Glance

最悪さいあく (saiaku) — It Sucks / Terrible

Exclamation and adjective of frustration

最悪さいあく can be used on its own as an exclamation, or before a noun: 最悪さいあくな日ひ (terrible day), 最悪さいあくなホテル (the worst hotel), 最悪さいあくな会社かいしゃ (the worst company).

Yuka

も〜、人生じんせい最悪さいあく！ (Man, my life sucks!)

Rei

あのレストラン、マジ最悪さいあく！ (That restaurant really sucks.)

Yuka

それは最悪さいあくだね！ (That really sucks!)

Rei

最悪さいあく！誰だれかが僕ぼくの席せきを取とってる！ (It sucks! Somebody took my seat!)

Yuka

初対面しょたいめんの印象いんしょうは最悪さいあくだったよ！ (Your first impression on me was terrible!)

Rei

いつも最悪さいあくのシナリオは考かんがえているよ。 (I always think about the worst-case scenario.)

Yuka

彼氏かれしと別わかれたよ。今日きょうは人生じんせいで最悪さいあくの日ひ！ (I broke up with my boyfriend. Today is the worst day of my life!)

最低さいてい (saitei) — You Suck / Despicable

Used especially for people’s bad behavior

最低さいてい carries the same slang force as 最悪さいあく, but it is especially used to call out someone’s behavior as despicable or morally low.

Rei

お前まえ最低さいていだな！ (You’re the worst!)

Yuka

あなたって最低さいていね！ (You really suck!)

Quick Quiz

Fill in the blank with 最悪さいあく or 最低さいてい

1. 財布を落としてしまった。（　　　）！(I dropped my wallet — frustration about a situation)
2. 約束を守らないなんて、あの人は（　　　）だ。(That person never keeps promises — judgment of a person’s character)
3. 今日は朝から（　　　）な一日だった。(Today was a terrible day from morning — describing the day itself)

Answers: 1. 最悪さいあく / 2. 最低さいてい / 3. 最悪さいあく

最悪さいあく is your go-to word for expressing that a situation is terrible. 最低さいてい is for calling out someone’s bad behavior. Both are casual and strong — use them in daily conversation to express frustration naturally, just like native speakers do!

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