tree 
(trē)
(trē)n.
1.
a. A perennial woody plant having a main trunk and usually a distinct crown.
b. A plant or shrub resembling a tree in form or size.
2.
a. Something that resembles a tree in form, especially a diagram or arrangement that has branches showing relationships of hierarchy or lineage.
b. Computers A structure for organizing or classifying data in which every item can be traced to a single origin through a unique path.
3.
a. A wooden beam, post, stake, or bar used as part of a framework or structure.
b. A saddletree.
4. Archaic
a. A gallows.
b. The cross on which Jesus was crucified.
tr.v. treed, tree·ing, trees
Idiom: 1. To force up a tree: Dogs treed the raccoon.
2. Informal To force into a difficult position; corner: the reporters finally treed the mayor.
3. To supply or cover with trees: a hillside that is treed with oaks.
up a tree Informal
In a situation of great difficulty or perplexity; helpless.
[Middle English, from Old English trēow; see deru- in the Appendix of Indo-European roots.]
treeless adj.