The term 'Tree Climber' can be summarized as a person who climbs trees for a variety of reasons. This could include recreational activities such as rock climbing, or professional activities such as arborists who climb trees to prune and maintain them. The crossword solution for this term is 'APE', which is an acronym for Aerial Pruning and Excavation. This type of work is often done by tree climbers, as they are able to access difficult-to-reach areas of the tree.