(Adj)Someone who performs wizardry with shit. Shitwizardy is an act involving finesse with not white, not black, but brown magic. Such as creating crap-golems or writing nonsensical descriptions for mundane objects.
"What do you mean you can't collect guano!"
"Its to stop the shitwizards casting fireballs!"
is used to replace the word SHIT without sounding that rude but can be used for other things due to the creator of the word hasnt come up with a true meaning.