An expression used to describe the feeling of that is which when the bowels produce an enormouse amount of gas and when this gas is expelled at such an extreme force that the gas itself must part ways, (hence the word crossways) at the fabric proceeding the anus. Whether it be underwear, cotton briefs, boxers, or just jeans, occasionally your very own bedding. If the fartcrossways is very extreme seepage will follow.
Bill Berditzman had such a bad case of gas today he experienced a fartcrossways while playing backgammon. He wasn't wearing any protection in his briefs so he had to change his underwear and pants, due to the fartcrossways.
by Gerald Cruthers December 27, 2011