まい
mai

Auxiliary Verb

1. probably isn't (doesn't, won't, etc.)

そうしたところで きみには なんもなるまい。
sōshita tokorode kiminiwa nanimo narumai.
You will gain nothing from doing that.
Auxiliary Verb

2. don't (doesn't) intend to; intend not to

相手 あいてチームはラインを えさせまいとしたのです。
aitechiimuwa rain'o koesasemaito shita nodesu.
The other team tried to keep them from crossing the line.
Auxiliary Verb

3. must not; (when used in an imperative sentence) don't