[tree-neyl, tren-l, truhn-l] 
| a wooden pin that swells when moist, used for fastening together timbers, as those of ships. |
| tree·nail or tre·nail (trē'nāl', trěn'əl, trŭn'əl) n. A wooden peg that swells when wet and is used to fasten timbers, especially in shipbuilding. |
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