posted 07-24-99 04:20 PM
I tend to agree with your definition. One cannot be prescriptive about such things as like many words, the term 'castle' is slowly broadening to take on more general meanings.However, in the medieval, historical sense of the word, I would define a castle as a fortified structure which usually had a residential function (even though the accomodation may have been used on an irregular basis). To my mind castles are also inseperable from feudal society.
Of course the nature of medieval castles and their functions changed over time from the timber functionality of early Norman structures to the palatial castles of the late medieval period, the defences of which were more apparent than real.
As to temporary structures, one can argue that mottes erected during periods of warfare can be accepted as 'castles' if they fulfilled the same basic functions as a more permanent castle.
Many other features ranging from Iron Age forts to mansions have the word 'castle' in their names, but they do not have the characteristics I have described. As essentially feudal structures, castles are found across Europe and I would also include those in Japan. In North America on the other hand, the term is used in a different sense to my understanding of the word.
This is only a very general answer to your question. One can scarcely do justice to such an enormous subject in so few words and no doubt others will have their own opinions on the matter.
Geoff.