ravelin
Concise Oxford English Dictionary © 2008 Oxford University Press:
ravelin /ˈravlɪn/
▶noun historical an outwork of fortifications, with two faces forming a salient angle, constructed beyond the main ditch and in front of the curtain.
– origin C16: from Fr., from obs. Ital. ravellino, of unknown origin.
'ravelin' also found in these Oxford entries:
