[tree] 
noun, verb, treed, tree⋅ing.| 1. | a plant having a permanently woody main stem or trunk, ordinarily growing to a considerable height, and usually developing branches at some distance from the ground. |
| 2. | any of various shrubs, bushes, and plants, as the banana, resembling a tree in form and size. |
| 3. | something resembling a tree in shape, as a clothes tree or a crosstree. |
| 4. | Mathematics, Linguistics. tree diagram. |
| 5. | family tree. |
| 6. | a pole, post, beam, bar, handle, or the like, as one forming part of some structure. |
| 7. | a shoetree or boot tree. |
| 8. | a saddletree. |
| 9. | a treelike group of crystals, as one forming in an electrolytic cell. |
| 10. | a gallows or gibbet. |
| 11. | the cross on which Christ was crucified. |
| 12. | Computers. a data structure organized like a tree whose nodes store data elements and whose branches represent pointers to other nodes in the tree. |
| 13. | Christmas tree. |
| 14. | to drive into or up a tree, as a pursued animal or person. |
| 15. | Informal. to put into a difficult position. |
| 16. | to stretch or shape on a tree, as a boot. |
| 17. | to furnish (a structure) with a tree. |
| 18. | up a tree, Informal. in a difficult or embarrassing situation; at a loss; stumped. |
| tree (trē) n.
[Middle English, from Old English trēow; see deru- in Indo-European roots.] tree'less adj. |
| tree (trē) Pronunciation Key
Any of a wide variety of perennial plants typically having a single woody stem, and usually branches and leaves. Many species of both gymnosperms (notably the conifers) and angiosperms grow in the form of trees. The ancient forests of the Devonian, Mississippian, and Pennsylvanian periods of the Paleozoic Era were dominated by trees belonging to groups of seedless plants such as the lycophytes. The strength and height of trees are made possible by the supportive conductive tissue known as vascular tissue. |
up a tree
In a difficult situation, as in They found the drugs in his suitcase, so he was up a tree. This expression alludes to an animal, such as a raccoon or squirrel, that climbs a tree for refuge from attackers, which then surround the tree so it cannot come down. [Colloquial; early 1800s]