A long pier or breakwater forming part of the sea defences of a port. It can be built either in the form of a detached mole constructed entirely in the sea or with one end of it connected to the shore. The ports of Dover and Gibraltar, for example, are protected by three moles, two of them attached to the shore with a detached mole to seaward, providing an entrance to the harbour at each end of it. In the distant past the word, sometimes written as mole-head, was also used, wrongly, to describe a harbour protected by a mole.
Subjects: Maritime History — Warfare and Defence.