Definitions of retrospective
a retrospective law or decision takes effect from a date in the past before the law was introduced or before the decision was made
Statutes do not operate in a retrospective fashion in respect to substantive law.
There are multiple definitions - click on the translation that matches your context.
retroativo means:
adjetivo
full
adjective
a retrospective law or decision takes effect from a date in the past before the law was introduced or before the decision was made
Statutes do not operate in a retrospective fashion in respect to substantive law.