a small circular tower for coastal defence, formerly much used in Europe
Word origin
C18: after Cape Mortella in Corsica, where the British navy captured a tower of this type in 1794
Martello tower in American English
(mɑrˈtɛloʊ)
noun
[alsom- t-]
a circular fort of masonry, formerly built on coasts to protect against invaders
: also marˈtellonoun
Word origin
It martello, a hammer, folk etym. substitution for mortella, a tower, after Mortella, cape in Corsica, where such a tower was attacked by the English fleet (1794)