勿れ

なかれ
must not
do not
be not

* * *

なかれ【勿れ】

be not; do not; should [ought, must] not; be warned 《against…》.

●気にするなかれ. Don't let it bother [trouble, worry] you.

・正を踏んで恐るるなかれ. Abide by justice and be not afraid. | Be just and fear not.

・笑うなかれ, そのときは真剣だったのだ. Don't laugh. I was in (dead) earnest at the time.