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

• Lexulous
• Wordscraper
• Wordosaur

ad. Following, afterwards in either time or place.

ad. accordingly, therefore (implying a logical connection or deduction)

ad. At a later time; afterwards.

In a subsequent manner; at a later time.

ad. happening at a time subsequent to a reference time

"The Taepings at Nankin determined to effect its relief, and a large force was placed under the orders of an officer named Li, but whom it will be more convenient to designate by the title subsequently conferred on him of"

subsequent    subsequence    subsequential   

afterwards