In german medicine it’s still completely fine to use. Retard capsulas for example is medicine that will have a delayed effect after taking them. Someone with brain damage who has issues following a flashlight with his eyes has a retarded response.
In English, it’s also pretty fine outside of developmental disorders. It’s common to refer to fire-retardant fabric. Adjusting timing in an engine is retarding or advancing.
In german medicine it’s still completely fine to use. Retard capsulas for example is medicine that will have a delayed effect after taking them. Someone with brain damage who has issues following a flashlight with his eyes has a retarded response.
In English, it’s also pretty fine outside of developmental disorders. It’s common to refer to fire-retardant fabric. Adjusting timing in an engine is retarding or advancing.