An exclamation and expletive comment/oath regarding ridiculously high price of gasoline and obscene profits of the oil companies. Abbreviated and combined phrase "Fuck Exxon." (Fuck + Exxon = Fuxxon) Like a more forceful way of saying "Oh My" when remarking about high gas prices and excessive profits of oil companies.
Gas is now $3.25 a gallon. Fuxxon me!