This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

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ad. At a later or succeeding time.

ad. At a later or succeeding time.

ad. happening at a time subsequent to a reference time

"But, as a rule, if she did or said the wrong thing, she became painfully conscious of the fact immediately afterwards -- indeed, it was generally _afterwards_ that she grasped the full meaning of most things."

afterward   

before    now    beforehand   

subsequently    thereupon    thereon    thereafter    so