sledge·ham·mer 
(slĕjhăm′ər)
(slĕjhăm′ər)n.
A long heavy hammer, often wielded with both hands, used for driving wedges and posts and for other heavy work.
tr.v. sledge·ham·mered, sledge·ham·mer·ing, sledge·ham·mers
To strike with or as if with a sledgehammer.
adj.
Ruthlessly severe; crushing: sledgehammer prosecutorial tactics.
[Middle English slegge (from Old English slecg) + HAMMER.]