Tree (tr), n. [OE. tree, tre, treo, AS. treó, treów, tree, wood; akin to OFries. tr, OS. treo, trio, Icel. tr, Dan. træ, Sw. trä, träd, Goth. triu, Russ. drevo, W. derw an oak, Ir. darag, darog, Gr. dry^s a tree, oak, do`ry a beam, spear shaft, spear, Skr. dru tree, wood, dru wood. √63, 241. Cf. Dryad, Germander, Tar, n., Trough.] 1. (Bot.) Any perennial woody plant of considerable size (usually over twenty feet high) and growing with a single trunk.