to roar: to let out the deep, resounding cry of a lion, or a sound like it
At its core this word is the roar of a lion. It names not just any loud noise but the specific, deep, terrifying cry a lion gives, most often as it closes on its prey. Almost everywhere the word appears, a lion is either the actual subject or the picture behind the sound.
Because a lion's roar means danger and unstoppable power, the prophets use the word for God. When the LORD "roars from Zion," it is the announcement of judgment: a sound that makes the land mourn and people tremble, exactly as prey freezes at a lion's cry (Hosea 11:10 pictures God this way, "he roars like a lion"). The same image turns the other way to picture Israel's enemies and its own corrupt leaders as roaring lions tearing at their victims.
Two uses step outside the lion frame. Once the word describes a person so crushed by pain that his cry is a raw groan rather than ordinary speech, and once it describes triumphant enemies bellowing inside God's own sanctuary. In every case the shared idea is a loud, deep, uncontrollable cry that signals overwhelming force, whether the force is a beast, an army, God, or grief.