—adj.
1. directed to the past; contemplative of past situations, events, etc.
2. looking or directed backward.
3. retroactive, as a statute.
—n.
1. an art exhibit showing an entire phase or representative examples of an artist's lifework.
2. any exhibition or series of showings or performances, as of musical works or motion pictures, representing the work of an artist or performer over all or a major part of a career: a retrospective of John Ford's movies.
http://dictionary.infoplease.com/retrospective
Retrospective (from Latin retrospectare, "look back") generally means to take a look back at events that already have taken place. For example, the term is used in medicine, describing a look back at a patient's medical history or lifestyle.
more...........
http://www.answers.com/topic/retrospective