Part of speech: Adverb
happening at a time subsequent to a reference time
Example: he apologized subsequently; he's going to the store but he'll be back here later; it didn't happen until afterward; two hours after that
Later on, Later, Afterwards, Subsequently, Afterward
after – A related word in the same word family.
ward – A related word in the same word family.
Technical fields like law and medicine preserve Latin and Greek because precision matters more than simplicity.