\Ou`bli`ette"\, n. [F., fr. oublier to forget, fr.
(assumed) LL. oblitare, L. oblivisci, p. p. oblitus.]
A dungeon with an opening only at the top, found in some old
castles and other strongholds, into which persons condemned
to perpetual imprisonment, or to perish secretly, were
thrust, or lured to fall.

      Sudden in the sun An oubliette winks. Where is he?
      Gone.                                    --Mrs.
                                               Browning.