カス

Japanese Slang Japanese ★★★★ 4/5 very-casual カスkasu
Reading カス
Romaji kasu
Kanji breakdown From 粕/滓 (kasu, dregs/sediment/residue). Written in katakana for the slang insult usage
Pronunciation /ka.sɯ/

Meaning

Scum, worthless — a harsh insult meaning someone or something is the absolute lowest quality, like dregs or sediment.

From 粕/滓 (kasu, dregs/sediment/residue left at the bottom), カス is used as a cutting insult for people or things considered utterly worthless. It's harsher than ダメ (no good) or クズ (scrap), carrying a sense of being not just bad but the leftover waste after everything useful has been taken. In gaming culture, it describes terrible plays, items, or pulls. When directed at people, it's a serious insult that can cause real conflict.

Examples

  1. 人の悪口ばっかり言う奴はカスだよ。 Anyone who does nothing but talk trash about others is scum.
  2. あのプレイはカスすぎて笑えない。 That play was so trash you couldn't even laugh at it.
  3. カスみたいな扱いされて腹立った。 I was treated like garbage and it pissed me off.

Usage Guide

Context: internet, gaming, casual conversation

Tone: aggressive, contemptuous

Do Say

  • 自分のことカスだと思ってたけど、最近ちょっとマシになった。 (I used to think I was worthless, but I've gotten a little better recently.)
  • カスみたいなガチャ結果で萎えた。 (My gacha results were garbage and I lost all motivation.)

Don't Say

  • 人に「カス」と直接言うのは喧嘩を売っているのと同じ (Calling someone カス to their face is essentially picking a fight)

Common Mistakes

  • Thinking カス is mild or playful — it's a genuinely harsh insult, stronger than ダメ or 下手
  • Not knowing the compound forms: ゴミカス (garbage scum), 人間のカス (human scum/dregs of humanity)

Origin & History

From 粕/滓 (kasu, dregs/sediment/residue). Originally referred to the leftover waste from brewing sake or pressing oil. The metaphorical use as an insult for worthless people or things has been in Japanese for centuries.

Cultural Context

Era: Long-standing insult, amplified by internet culture

Generation: All ages

Social background: Universal (negative)

Regional notes: Used nationwide. The brewing/sake origin (酒粕 = sake lees) is part of traditional Japanese vocabulary.

Related Phrases

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