The hard, pointed mouths of birds, or someone's nose (used informally).
From Old French bec, from Latin beccus. The origin before Latin is uncertain, possibly from a Celtic language. The word transferred to mean nose because of the shape.
Medieval knights called the prominent snout armor on jousting helmets a 'beak'—today we'd look at those and see a bird's face staring at us, but they saw the weapon itself.
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