Definitions
1.AdjectiveOf, or relating to, the past, past times, or the way things were.
2.AdjectiveAffecting things past; retroactive, ex post facto.
3.NounPast fashions or trends.
4.NounAbbreviation of retrorocket.
5.NounAbbreviation of retrospective.
6.NounA chess puzzle of retrograde analysis, requiring the solver to work out the history of moves leading to the position presented.