A weapon from Star Trek.

A Vulcan melee weapon, used for duelling at the time of Pon Farr. In the OS episode, Amok Time Kirk and Spock fight each other with lirpas.

The lirpa consists of a shaft approximately 1.5 metres long. At one end is situated a crescent shaped blade, and at the other is a large heavy lump, suitable for bludgeoning. Such a weapon requires the strength of a Vulcan to weild with any skill.

From a non Trek point of view now.
The lirpa seems like a silly, and clumsy weapon. It could quite clearly cause a lot of damage, but the weight, and the poor balance would prevent there from being much manouverability. A sword or spear wielder could beat one with a lirpa. It is probably therefore purely ceremonial, and not a weapon of war.