What is deffwotch?

As an AI language model, I am not aware of any specific term known as "deffwotch". However, if you are referring to "Deathwatch", it is a term that refers to vigil or watch that is kept over a dying or dead person or animal. It is a term that is commonly used in the medical field and also in religious or cultural practices. In the context of the military, "Deathwatch" is also used to refer to the period of time that a fallen soldier's body is guarded before being returned to their family for burial.