Merriam-Webster Collegiate Dictionary - mallet

 noun  Etymology: Middle English maillet, from Anglo-French, diminutive of mail hammer — more at maul  Date: 15th century a hammer with a typically barrel-shaped head: as  a. a tool with a large head for driving another tool or for striking a surface without marring it  b. a long-handled wooden implement used for striking a ball (as in polo or croquet)  c. a light hammer with a small rounded or spherical usually padded head used in playing certain musical instruments (as a vibraphone)