E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Miolnier (3 syl.) [the crusher].
The magic hammer of Thor. It would never fail to hit a Troll; would never miss to hit whatever it was thrown at; would always return to the owner of its own accord; and became so small when not in use that it could be put into Thors pocket. (Scandinavian mythology.)