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1.
Noun:

Something which is known to have happened or to exist, especially something for which proof exists, or about which there is information. It can be used at the end of a sentence emphasize a statement's truth.

It can also be pronounced "Fact-a-fucking-mund-o"
"That Dale Winton is a right fucking nonce. Factamundo."

"Women should be banned from football. Factafuckingmundo."

by Doogster April 01, 2007
 
2.
A word that directly relates to the word 'fact'. However due to the insurgence of latinos, they have began to use the term factamundo, separating them selves from the Spanish who say: 'Factamento'
Factamundo: Bruce Willis is not balding...
by awsome-0- November 03, 2009