1ret·ro·spec·tive 
/ˌrɛtrəˈspɛktɪv/ adjective
/ˌrɛtrəˈspɛktɪv/ adjective 1 : of or relating to the past or something that happened in the past
▪ They issued a retrospective report. ▪ a retrospective analysis of what went wrong ▪ The museum is having a retrospective exhibit of the artist's early works. 2 : effective from a particular date in the past
▪ retrospective [=(more commonly) retroactive] laws
▪ They issued a retrospective report. ▪ a retrospective analysis of what went wrong ▪ The museum is having a retrospective exhibit of the artist's early works.
▪ retrospective [=(more commonly) retroactive] laws
— ret·ro·spec·tive·ly adverb
▪ Their actions could only be understood retrospectively. ▪ The new law will be applied retrospectively.
▪ Their actions could only be understood retrospectively. ▪ The new law will be applied retrospectively.
