ETYM AS. aefteweard, a., behind. Related to Aft, and -ward (suffix). The final s in afterwards is adverbial, orig. a genitive ending.
Afterward.
Happening at a time subsequent to a reference time

ETYM Originally the same word as than. Related to Than.
1. At that time.
2. In that case or as a consequence.
3. Subsequently or soon afterward (often used as sentence connectors); SYN. so, and so, and then.