A d'ktahg is a traditional Klingon dagger in Star Trek. It has three blades: one long and broad and two short retractable ones that spring out the sides. It is used both in hand-to-hand combat and Klingon rituals.

It's worth mentioning that a D'ktahg is an extremely personal weapon to a Klingon warrior. Each blade's handle is etched with its owners family name and is considered a symbol of its wielder's status in the empire as well as a physical manifestation of his honor.

For this reason, relieving a warrior of his d'ktahg (particularly if the blade's owner isn't killed in the process) is considered a grave insult to that warrior as well as his house - apart from the shame brought on by a warrior losing his weapon/honor, not protecting the blade with his life is a further disgrace. It conveys the attacker's belief that the warrior was too pathetic to kill.