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Fomg is a term generally used to the same extent as zomg. Only with an F.

Fomg is also a misspelling of omfg.
Fomg u suk lolz!!11!one!!1!1
by Masq January 09, 2005
Fucking Oh My God.

Pronounced: Foe My God
"Fomg! I just shat my undercrackers!"
by Kieran Gabriel July 26, 2006