As a noun mallet
is a type of articulated locomotive, in which there are two powered trucks, with the rear truck being rigidly attached to the main body and boiler of the locomotive, while the front powered truck is attached to the rear by a hinge, so that it may swing from side to side, and with the front end of the boiler resting upon a sliding bearing on the swinging front truck.
As a proper noun mallet
is (cryptography) often the malicious party in examples of threat scenarios (synonym: mallory) see (alice and bob
As a verb malled is