redoubt

noun Fortification.

1. an isolated work forming a complete enclosure of any form, used to defend a prominent point.
2. an independent earthwork built within a permanent fortification to reinforce it.

noun

1. Mount, an active volcano in S Alaska, on the Alaska Peninsula: highest peak in the Aleutian Range. 10,197 feet (3108 meters).

noun

1. an outwork or detached fieldwork defending a pass, hilltop, etc
2. a temporary defence work built inside a fortification as a last defensive position

n.

also redout, “small, enclosed military work,” c.1600, from French redoute (17c.), from Italian ridotto, earlier ridotta, “place of retreat,” from Medieval Latin reductus “place of refuge, retreat,” noun use of past participle of reducere “to lead or bring back” (see reduce). The -b- was added by influence of unrelated English redoubt (v.) “to dread, fear” (see redoubtable). As an adjective, Latin reductus meant “withdrawn, retired; remote, distant.”