Typically, "aftermath" meant to describe the period of time after something bad has happened.
- the effects of something traumatic
- the consequences of an event
- after effects
- A lot of countries sent help in the aftermathof the earthquake.
- There are numerous videos online that show the aftermathof the tsunami that hit Thailand a few years ago.
- Our family had to stand together in the aftermathof the scandal.
- We are all waiting to see what the aftermath of the fight will be.
The first part of the word is easy enough to decipher. The second part has quite interesting origins. The word math comes from the Old English mæth that means "mowing," from mamacrwan "to mow"
In the 1500s the term was used to describe a second, or even third crop of grass that was planted in the same location as one that had already been harvested. Thus, the farmers had to return to do a second mowing. During the 16th and 17th centuries, the word was used in a variety of different forms, like:
aftercrop (1560s), aftergrass (1680s), lattermath
The figurative sense of the word, as we use it today has been used since the 1650s.