This is when a small penis is overlaped by fat or stomach so nobody can see it.
David "fatass" Dixon has a dicklap because he is a fatass with a VERY small dick . Sucks for him he cant jack-off .
A dicklap is when all the fat from your fatass stomach overlaps your tiny dick so it can't be seen.
Fatass patrick Kippert probably has a dicklap with all that fat stretch on his belly, and we all know he has a small zub.