- tree:
N In computer science, a tree is a widely used abstract data type that represents a hierarchical tree structure with a set of connected nodes.

N In graph theory, a tree is an undirected graph in which any two vertices are connected by exactly one path, or equivalently a connected acyclic undirected graph.

N In set theory, a tree is a partially ordered set such that for each t ∈ T, the set {s ∈ T : s < t} is well-ordered by the relation <.

N In descriptive set theory, a tree on a set is a collection of finite sequences of elements of such that every prefix of a sequence in the collection also belongs to the collection.

N a 2001 album by Gaelic Storm.

N In computing, tree is a recursive directory listing command or program that produces a depth-indented listing of files.

N A tree is a perennial woody plant.

N In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves.

N a 1978 historical novel by Filipino National Artist F. Sionil José.

N an album by Irish folk singer Johnny Duhan.

N In automata theory, a tree is a particular way of representing a tree structure as sequences of natural numbers.

N (stylized as TREE) the seventh Japanese studio album (fourteenth overall) by South Korean pop duo Tohoshinki, released by Avex Trax on March 5, 2014.

N a controversial high inflatable sculpture by the artist Paul McCarthy that was briefly installed in the Place Vendôme in Paris in October 2014 as part of a exhibition called "Hors les murs".

N the second studio album by Japanese rock band Sekai no Owari.

N Keith Barry, known professionally as Tree, is an American musician and multi-instrumentalist.