Having the characteristics of a tree. (of a plant)
1684, Thomas Browne, “Observations upon Several Plants Mention’d in Scripture” in Certain Miscellany Tracts, London: Charles Mearne, pp. 28-29,
For the Parable may not […] imply any or every grain of Mustard, but point at such a grain as from its fertile spirit, and other concurrent advantages, hath the success to become arboreous, shoot into such a magnitude, and acquire the like tallness.
1918, Edgar Rice Burroughs, Out of Time’s Abyss in The Complete Works of Edgar Rice Burroughs, Hastings, UK: Delphi Classics, 2014, Chapter 1,
dense forests of eucalyptus and acacia and giant arboreous ferns with feathered fronds waving gently a hundred feet above their heads
Covered or filled with trees.
(obsolete) Growing on trees.
(obsolete, anatomy) Having a tree-like, branching structure.
1698, William Cowper, The Anatomy of Humane Bodies, Oxford: S. Smith and B. Walford, Table 56,
[…] [the] Internal Concave Surface [of the Placenta Uterina] next the Amnios, Appears Cover’d with the Chorion; under which the Arboreous Disposition of its Blood-Vessels are elegantly Exprest.