Of uncertain origin—originally the calcined ashes of seaweed used in glassmaking, later transferred to the living plant.
Large brown seaweeds of the order Laminariales that grow in underwater forests in shallow ocean waters.
Of uncertain origin. First recorded meaning 'calcined ashes of seaweed,' used in glassmaking and soap production. The shift to mean the living plant came later. Possibly related to Middle English 'culpe' (the ashes), but the deeper etymology remains obscure. Key roots: kelp / culp (Middle English: "seaweed ash (uncertain further)").