Source : Webster's Revised Unabridged Dictionary (1913)

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 : WordNet®

arboreal
     adj 1: of or relating to or formed by trees; "an arborous roof"
            [syn: {arborical}, {arborary}, {arborous}]
     2: inhabiting or frequenting trees; "arboreal apes" [syn: {arboreous},
         {tree-living}] [ant: {nonarboreal}]
     3: resembling a tree in form and branching structure;
        "arborescent coral found off the coast of Bermuda";
        "dendriform sponges" [syn: {arboreous}, {arborescent}, {arboresque},
         {arboriform}, {dendriform}, {dendroid}, {dendroidal}, {treelike},
         {tree-shaped}]