Famtrad is neopagan slang for "family tradition". This isn't whose house you go to for holidays, however. This refers to the idea that a family has been passing down esoteric knowledge regarding "The Old Religion" since the takeover of another faith (usually Christianity). This often refers to some form of witchcraft, which is not necessarily Wicca, and is therefore sometimes referred to as hereditary witchcraft.
The attitude towards famtrads ranges from utter belief to utter disbelief. Many famtrad practices do not line up with what archaeologists have learned about Paleopaganism. Of course, it is likely that oral knowledge would shift with time, and there were some minor magical and shamanic groups in Europe. Even so, some people consider them to be a type of Mesopaganism.