High status fortified residences not capable of withstanding an army but able to resist an armed band. They are generally moated and may have a gatehouse with loops and crenellations. The difference between a small castle and a fortified manor house is a subjective one and may well be an artificial division in that for contemporary medieval citizens it may not have existed. David King did not use this term and preferred the term Strong House, since not all fortified high status houses were manorial, but use of his term Strong House has not been widely adopted possible because it is widely used as a synonym for bastle.
Such buildings did not require a licence to crenellate, despite some suggestions otherwise, and having a licence to crenellate does not mean a building was certainly fortified. However, all buildings issued a licence to crenellate are recorded under this group since they clearly were at least intended to be [re]constructed in a fortified style. It is clear that a good number of the houses granted licences to crenellate had only very slight defences such as a moat and maybe a thin walled stone gatehouse but otherwise were mainly timber buildings.
Also recorded under this label are a number of later medieval houses which are not generally considered 'defensive' but which used architectural styles that derived from military function. These houses are sometimes called 'castles of chivalry', they were almost purely residential with the administrative function of the manor often done elsewhere.