A wicked or evil person; a scoundrel or bad guy.
彼は若い頃、よく街の悪と言われていた。
He used to be called the town's bad guy when he was young.
まわりの人々は彼を悪だと噂していたが、真相は違った。
People around him gossiped that he was evil, but the truth was different.
その組織のリーダーは地域では悪として知られている。
The leader of that organization is known locally as a villain.
A naughty or badly behaved child; a brat.
あの子は小さいころから少し悪だったが、今は落ち着いた。
That child was a bit of a rascal when small, but is calm now.
先生に叱られても、まだ悪を直せない子がいる。
Even after being scolded by the teacher, there are kids who can't stop misbehaving.
近所で有名な悪の子は、よくいたずらをしていた。
The well-known naughty kid in the neighborhood often played pranks.
Used as a prefix meaning badness or mischief (as in compounds like '悪事' or '悪影響').
彼は若い頃、いくつかの悪事に手を染めていた。
He was involved in several wrongdoings when he was young.
あの薬は副作用で悪影響を及ぼすことがある。
That drug can sometimes have adverse effects as a side effect.
悪ふざけが度を越して問題になった。
A prank went too far and became a problem.
Used prenominally to indicate excess or lack of restraint (e.g., '悪ノリ' meaning going overboard).
彼は悪ノリして冗談を言いすぎ、皆の気まずくなった。
He went too far with the jokes, and it made everyone uncomfortable.
飲み会での悪乗りは時に問題を引き起こす。
Overdoing it at drinking parties can sometimes cause trouble.
節度を欠いた悪ふるまいは信頼を失う原因になる。
Excessive, unrestrained misbehavior can cause you to lose trust.