Arab (אָרַב) means to lurk, to lie in ambush, or to set a trap. It describes the action of concealing oneself in order to attack by surprise. The verb is used for military ambushes, for robbers lying in wait, and metaphorically for the wicked who secretly plot against the innocent.
The imagery of arab — the hidden enemy lying in wait — becomes a powerful description of how the devil operates: "Your adversary the devil prowls around like a roaring lion, seeking someone to devour" (1 Peter 5:8). The Psalms frequently contrast the ambushes of the wicked with the protection of God who sees all hidden things and shields His own from unseen danger.