Sting

Sting was an Elvish short sword made in Gondolin during the First Age.

Sting was an ancient blade, made by the Elves during the First Age and was lost during the Fall of Gondolin, the same battle in which Turgon fell and Glamdring was taken. Sting was a magical weapon used by Bilbo in The Hobbit, which he found in a troll-hoard along with Glamdring and Orcrist. Although it was just a knife by the standard of elves, it made a perfect sword for a Hobbit. Bilbo gives Sting to Frodo before the Fellowship set off from Rivendell. After the defeat of Sauron at the end of the Third Age, Frodo entrusted Sting to Sam and it became an heirloom of the Gamgee family.

It was named by Bilbo after fighting a giant spider in Mirkwood, where he used it to "sting" the beast, so to speak, Bilbo then went on to "sting" many other giant spiders. Like all weapons forged in Gondolin it glowed blue when orcs were near.

Gollum, who disliked anything made by the elves, was afraid of Sting. His fear aided Bilbo when he confronted Gollum in a cave at the base of the Misty Mountains in The Hobbit. It also helped Frodo tame Gollum (temporarily) in The Lord of the Rings.

The Films
In Peter Jackson's adaptations, Sting is depicted as vaguely leaf-shaped, with gently curving edges, such as Tolkien describe in his book. Engraved on the blade are Sindarin letters that read phonetically, "Maegnas aen estar nin dagnir in yngyl im". Translated they read, "Sting is my name; I am the spider's bane." According to the appendix of The Silmarillion, the element maeg in Sindarin means 'sharp' or 'piercing', and the Etymologies section in The Lost Road and Other Writings gives the meaning of the element nass as 'point', so "Maegnas" is literally translated as "sharp-point", that is, Sting.

In the books there is no mention that Bilbo had the blade inscribe.