A deed; anything stated and made certain.
- Nuttall's Standard dictionary of the English language. By Nuttall, P.Austin. Published 1914. (noun) (n.) (noun)

Usage examples:

15, 'Id isti vituperant factum atque in eo disputant contaminari non decere fabulas ...
- The Student's Companion to Latin Authors by George Middleton Thomas R. Mills
But when that Opposition, victorious in the general election of 1880, took office in April of that year, the officials in South Africa, whose guidance they sought, made light of Boer discontent, and declared that it would be impossible now to undo what had been done in 1877. Thus misled, the new Cabinet refused to reverse the annexation, saying by the mouth of the Under Secretary for the Colonies, " Fieri non debuit, factum valet."
- Impressions of South Africa by James Bryce
It says not debet factum fuisse, but debuit fieri.
- The English Language by Robert Gordon Latham