Tree′nail.
（Shipbuilding.) A cylindrical pin of hard wood used for securing planking to the frames, or parts to each other. Teak (Tectona grandis), a tree of India and Burmah, is much esteemed for this purpose, as it shrinks little and has no acrid juices to rust bolts. Oak is also much used. Treenails are from 1 to 1 3/4 inches in diameter. Compressed treenails are made by driving the steamed treenail through a tapering steel tube, so as to reduce them to 2/3 of their original diameter. The original words mean wooden nail. (Old English, treen, wooden.) They are tightened by wedges driven into each extremity.
