The word aforemention is not recognized by any of the authoritative English dictionaries.
The word most closely resembling aforemention is aforementioned .
Here's a list of synonyms for aforementioned .
Previously mentioned
“Quite apart from the aforementioned lovely inhabitants, the city itself is great.”
Existing or occurring at some time in the past
“As was the case in some aforementioned examples, the elite seem in many cases to have taken a commanding role in ensuring that their servants received proper treatment for their tumors.”
(this/that same ) Referring to a subject just mentioned or spoken about
Previously referred to or spoken of
The one or ones mentioned previously
“The judge then indicated that the aforementioned were to be set free.”
(the same ) The same thing as something previously spoken about
