(obsolete) A passion flower cultivated for its fruit. / (obsolete, figuratively) The cross on which Jesus was crucified.

The plant Nyctanthes arbor-tristis.

Gossypium arboreum, a species of cotton native to India, Pakistan and other tropical and subtropical regions of the Old World.

(computing theory) A purely functional tree-like data structure offering amortized constant time access to its "fingers" (leaves), used for the efficient implementation of other purely functional data structures.

(botany) A tree of the species Carya illinoinensis, the members of which are valued agriculturally for their fruit, the pecan, and the wood of the tree, pecan wood, used in woodworking as well as smoking meats.

Xanthostemon paradoxus, a species of shrub or tree.

(graph theory) A tree in which one vertex has been designated as the root.

(botany) Either of two trees, Cochlospermum religiosum and Cochlospermum vitifolium, of India and Latin America respectively.

(historical) The frame to which harness-pads are attached, for riding an animal.

A worm that lives in trees, feeding primarily upon woody material. / (figuratively, derogatory) A lowly, parasitic individual; slimeball, lowlife.