What is the X in X-mas?
to fall or slide down; to decline; to fall in value
His golf game is going south.
slang; goes south, going south, went south, gone south
"vanish, abscond," 1920s, American English, probably from mid-19c. notion of disappearing south to Mexico or Texas to escape pursuit or responsibility, reinforced by Native American belief (attested in colonial writing mid-18c.) that the soul journeys south after death.
[probably fr the notion of disappearing south of the border, to Texas or to the Mexican border, to escape legal pursuit and responsibility; probably reinforced by the widespread Native American belief that the soul after death journeys to the south, attested in American Colonial writing fr the mid-1700s; GTT, ''Gone to Texas, absconded,'' is found by 1839]