Bad Example, Bad Precedent
noun
A bad example is a bad example and is something you don't want. This is a formal expression and less common than 悪い例 (bad example) or 良くない例 (not good example).
あくれい
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
日本語を学ぶ時には、いい例だけでなく、悪例を学ぶことも必要です。
When learning Japanese, it is necessary to learn from good examples as well as bad examples.
コウイチは悪例のかたまりだ。
Koichi is a cluster of bad examples.
僕の両親は、今後の寝る時間に悪例を残すことになるからって、絶対に夜更かしさせてくれないんだ。
My parents never let me stay up late because they believed it would set a bad precedent for future bedtimes.