sleep with the fishes

Sleep with the fishes is the phrase used for someone who is killed and then their body in thrown into the water such as the ocean, river or lake. To be sleeping with the fishes, you are typically dead rather than sleeping, but you are underneath a body of water which has fish; typically an ocean but it can also be used for smaller bodies of water too. This phrase is commonly used in movies or television shows where someone threatens to kill them by saying they will soon be sleeping with the fishes.