The word "after-maths" means the consequences or results of a particular event. The antonyms for "after-maths" are "pre-events" or "before-effects." These words refer to the necessary actions or reactions that precede an event, such as preparation or prevention. In contrast, "after-maths" refers to the aftermath of an event, such as the aftermath of a natural disaster, war, or any other event that has left a significant impact on people or the environment. Therefore, the antonyms for "after-maths" are words that imply taking steps to avoid or mitigate the consequences of an event before it happens.