The Collaborative International Dictionary of English v.0.48:

Confessional \Con*fes"sion*al\, n. [F. confessional.]
   The recess, seat, or inclosed place, where a priest sits to
   hear confessions; often a small structure furnished with a
   seat for the priest and with a window or aperture so that the
   penitent who is outside may whisper into the priest's ear
   without being seen by him or heard by others.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Confessional \Con*fes"sion*al\, a.
   Pertaining to a confession of faith.
   [1913 Webster]

   Confessional equality, equality before the law of persons
      confessing different creeds.
      [1913 Webster]

WordNet (r) 3.0 (2006):

confessional
    n 1: a booth where a priest sits to hear confessions