(mathematics) A binary tree.

(mathematics, computer science) A data structure in which each node has at most two children, each node but the root has one parent, and there are no cycles.

(botany) Alternative spelling of sulfur tree

A privately-owned farm where trees, usually softwoods, are grown for eventual harvest.

(US, idiomatic) On an automobile (especially those produced from 1939 through the mid-1970s), a three-speed manual transmission whose gearshift lever is mounted on the steering column.

(botany) Any tree whose branches are covered with yellow club moss spores

Alternative spelling of three-on-the-tree

(US) An upright pole having hooks on which to hang coats or other clothing

(graph theory) A tree consisting of only a path (the spine or stalk of the tree) and vertices directly connected to (i.e. one edge away from) that path; a tree whose vertices with a degree of at least 3 are all surrounded by at most two vertices of degree two or greater.

(botany) A tree-like yucca, Yucca brevifolia, of the southwestern United States, with spiky leaves.