sledgehammer

Short definition from Wiktionary

Noun

1. 1
   A hammer that consists of a large, heavy, broad and flat block of metal (the head) attached to a handle typically 0.5 meter to 1 meter long. The sledgehammer's design is meant to allow it to be swung powerfully, and to distribute force over a wide area upon impact.

Verb

1. 1
   To strike (something) with a sledgehammer.

Adjective

1. 1
   Completely lacking grace and dexterity.