double dagger

例句：

1. 1.The assassin used a double dagger to stab his target from behind.
   刺客用一把双刃匕首从后面刺向目标。
2. 2.The thief carried a double dagger hidden in his sleeve.
   小偷藏在袖子里的是一把双刃匕首。
3. 3. The weapon was designed with a double dagger mechanism for added security.
   这把武器设计有双刃机制，以增加安全性。