Arboreal \Ar*bo"re*al\, a.

1. Of or pertaining to a tree, or to trees; of nature of trees. --Cowley.

2. Attached to, found in or upon, or frequenting, woods or trees; as, arboreal animals.

Woodpeckers are eminently arboreal. --Darwin.

Source: Webster's Revised Unabridged Dictionary (1913)