Though the direct translation would be Obsidian-Sharp-Knife, the correct translation would most likely be Sharp-Obsidian-Knife.
Some TzHaar-Xil will use Toktz-xil-ek as a companion weapon to a Toktz-xil-ak, hitting the player with the dagger, then the sword, though it will only register as one hit.
Before the Evolution of Combat, this weapon was a slashing weapon, with attack styles similar to a scimitar (though it could still stab).