Orcrist was the weapon of the Dwarf chieftain Thorin Oakenshield, from the novel The Hobbit. As in in Norse culture, the swords of J.R.R Tolkien's Middle-Earth oftentimes had proper names. Likewise in The Hobbit, Gandalf the Grey owned Glamdring, and Bilbo Baggins had Sting, which he later bequeathed to his nephew Frodo (Lord of the Rings). All of these weapons were Elven-made which were particularly deadly to the fell beasts of Middle-Earth, due to the Elven magic they held.
As the name suggests, Orcrist means "Goblin (Orc) Cleaver"