Pile-tower, or Pele-tower

Pile-Tower, Or Pele-Tower an architectural term, seems to have signified a small fortress, dwelling, or tower, capable of being defended against any sudden marauding expedition. Church towers appear to have been sometimes used for the same purpose. Some of these towers, which were used for habitations, have had additions made to them subsequent to their erection. Heifer-haw tower, near Alnwick, and a tower in Corbridge churchyard, were probably pele-towers only. Pile, a fortress, occurs only in names of places in the Isle of Man, Lancashire, and the neighboring parts, but it is an archaic term not exclusively northern.