Word of the Day

: April 28, 2023

arboreal

adjective ahr-BOR-ee-ul

What It Means

Arboreal is a literary term that means “of or relating to trees.” It can also mean “living in or often found in trees,” as in “arboreal monkeys.”

// Despite taking weekly hikes on the same trail, she never ceases to be amazed by the forest’s arboreal beauty.

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arboreal in Context

“[The satanic leaf-tailed gecko's] mottled brown skin, replete with mossy splotches and vein-like ridges, makes it the perfect imitation of a decaying leaf. Any predator clever enough to see through its arboreal disguise and mount an attack will be in for a fright. The leafy gecko opens its mouth, sticking out a blood-red tongue and unleashing a chilling scream that will frighten off the boldest of predators.” — Holly Barker, Discover Magazine, 7 Oct. 2022

Did You Know?

Arboreal took root in English in the 17th century, at a time when language influencers were eager to see English take on words from Latin and Greek. Apparently unsatisfied with the now-obsolete word treen (“of, relating to, or derived from trees”), they plucked arboreal from the Latin arboreus, meaning “of a tree”; its ultimate root is arbor, meaning “tree.” That root arborized—that is, branched freely (to use the term figuratively): English abounds with largely obscure words that trace back to arbor, meaning “tree.” Generally synonymous with arboreal are arboraceous, arborary, arboreous, and arborous. Synonymous with arboreal specifically in the sense of “relating to or resembling a tree” are arborescent, arboresque, arborical, and arboriform. Arboricole is a synonym of arboreal in its “inhabiting trees” sense. (The influencers may have overdone it a bit.) Arboreal is far more common than any of these, but other arbor words also have a firm hold in the language: arborvitae refers to a shrub whose name translates as “tree of life”; arboretum refers to a place where trees are cultivated; and arboriculture is the cultivation of trees. And of course we can't forget Arbor Day, which since 1872 has named a day set aside for planting trees. Despite its spelling, however, the English word arbor, which refers to a garden shelter of tree boughs or vines twined together, has a different source: it came by way of Anglo-French from the Latin herba, meaning “herb” or “grass.”