Bastile, n. [F. bastille fortress, OF. bastir to build, F. b.].
A tower or an elevated work, used for the defense, or in the siege, of a fortified place. [1913 Webster]
"The high bastiles . . . which overtopped the walls."
[1913 Webster]
“The Bastille”, formerly a castle or fortress in Paris, used as a prison, especially for political offenders; hence, a rhetorical name for a prison. [1913 Webster]