In mythology, Thor's hammer is frequently anglicized as Mjolnir, though there are many alternate spellings. The hammer is also called Mjolnir in the 2011 movie "Thor" and its sequels. The name roughly translates as "that which smashes."
In mythology, Mjolnir is forged by Sindri and Brokkr to win a bet with Loki. It is supernaturally powerful and accurate when thrown.
An actual hammer of Thor was unearthed by archaeologists in Denmark in 2014. The hammer most likely did not actually belong to a Norse god, but was crafted by an artisan sometime in the 10th century in accordance with the Thor legends.