A kid's word that means a plunger for a toilet. "Fopo" is onomatpoeic for the sounds produced by the plunger in the water of the toilet bowl: "fo" for the downstroke and "po" for the upstroke, especially when there is a popping sound if the flanges of the plunger get caught under the rim of the whirlpool.
Mommy, is Daddy gonna use the fopo plunger?