A graft is a piece of healthy skin or bone, or a healthy organ, which is attached to a damaged part of your body by a medical operation in order to replace it.
If a piece of healthy skin or bone or a healthy organ is grafted onto a damaged part of your body, it is attached to that part of your body by a medical operation.
If a part of one plant or tree is grafted onto another plant or tree, they are joined together so that they will become one plant or tree, often in order to produce a new variety.