'Sound' in the Bible

Then the sailors became afraid and every man cried to his god, and they threw the cargo which was in the ship into the sea to lighten it for them. But Jonah had gone below into the hold of the ship, lain down and fallen sound asleep.

The captain approached him and said, “What are you doing sound asleep? Get up! Call to your god. Maybe this god will consider us, and we won’t perish.”