- tree:
n A perennial woody plant, not exactly defined, but differentiated from a shrub by its larger size (typically over a few meters in height) or growth habit, usually having a single (or few) main axis or trunk unbranched for some distance above the ground and a head of branches and foliage.

n Any plant that is reminiscent of the above but not classified as a tree (in any botanical sense).

n An object made from a tree trunk and having multiple hooks or storage platforms.

n A device used to hold or stretch a shoe open.

n The structural frame of a saddle.

n (graph theory) A connected graph with no cycles or, if the graph is finite, equivalently a connected graph with n vertices and n−1 edges.

n (computing theory) A recursive data structure in which each node has zero or more nodes as children.

n (graphical user interface) A display or listing of entries or elements such that there are primary and secondary entries shown, usually linked by drawn lines or by indenting to the right.

n Any structure or construct having branches representing divergence or possible choices.

n The structure or wooden frame used in the construction of a saddle used in horse riding.

n (in the plural, slang) Marijuana.

n (obsolete) A cross or gallows.

n (chemistry) A mass of crystals, aggregated in arborescent forms, obtained by precipitation of a metal from solution.

n (cartomancy) The fifth Lenormand card.

v (transitive) To chase (an animal or person) up a tree.

v (transitive) To place in a tree.

v (transitive) To place upon a tree; to fit with a tree; to stretch upon a tree.

v (intransitive) To take refuge in a tree.

n (mathematics) An extremely fast-growing function based on Kruskal's tree theorem.

n A surname.

n (uncountable, mathematics) Alternative letter-case form of TREE. [(mathematics) An extremely fast-growing function based on Kruskal's tree theorem.]

n (mathematics) Alternative letter-case form of TREE [(mathematics) An extremely fast-growing function based on Kruskal's tree theorem.]