a pirate along the Barbary Coast
"The local fishermen refused to trade with the corsair who had been raiding ships off the Barbary Coast for months."
a swift pirate ship (often operating with official sanction)
"The corsair swept through the harbor, capturing merchant vessels while flying the flag of his sovereign state."
A French privateer, especially from the port of St-Malo
"The local historian explained that the legendary corsair who raided English ships actually hailed from the bustling port of St-Malo."