Limbing is an arboricultural word that means removing unwanted limbs from a tree. When should homeowners pay particular attention to the need to have a tree limbed? When large scaffold branches hang dangerously over their house or a neighbor's home. In the latter case, take careful notice of the legal issues that may be involved.
Limbing work in which large tree branches are involved is best performed by arborists or a reputable tree service. But the term "limbing," more broadly speaking, can be properly applied to the removal of any limbs from any tree, regardless of size.
If a large branch from a tree that you own currently hangs over a structure on your or somebody else's property, you may wish to look into hiring a tree service before property damage occurs.