The term "incompactnesses" refers to the quality of not being compact or closely packed. There are several synonyms that can be used to describe this lack of density, including looseness, sparseness, thinness, and openness. Other related concepts that could be used to express incompactness include airiness, lightness, porousness, or even insufficiency. Each of these words evokes a slightly different nuance and might be more appropriate in different contexts, but they all share the idea of something that is not tightly compressed or densely packed. Synonyms provide a valuable tool for enriching language and expanding the range of expression, helping to convey more precisely the intended meaning of a text.