This is Tarski's definition for disjointness; this is actually the converse of common-part-with:disjoint(x,y) <=> not(common-part-with(x,y)). Leonard-Goodman prefer disjoint as primitive and they define part from it. Consider that there exist distributed wholes having non-connected parts -societies with members, collections, etc.- but this is not to say that this definition of disjoint does not hold; in fact, distributed wholes are characterized by some particular meronymic notion of part (see theory:'meronymy').
(<=> (Mereo-Disjoint ?A ?B)
(And (Not (Common-Part ?A ?B)) (Mereological-Relation ?A ?B)))