Billethead
Bil´let`head`
(bĭl´lĕt`hĕd)| n. | 1. | (Naut.) A round piece of timber at the bow or stern of a whaleboat, around which the harpoon line is run out when the whale darts off. |
Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.