hob (n.) Look up hob at Dictionary.com
"side of fireplace," 1670s, alteration of hubbe (1510s), of unknown origin, perhaps somehow related to the first element in hobnail.
Hob (n.) Look up Hob at Dictionary.com
"clown, prankster," short for hobgoblin (q.v.). Hence, to play (the) hob "make mischief" (by 1834).