a semisolid is a substance that is in between a solid and a liquid. another name for a semi-solid is a quasi-solid. mayonnaise is an example of a semi-solid. mayonnaise does not hold its shape like a solid but does not flow like a liquid. a substance like gel or cream is another example of a semi-solid. normally semi-solids are covalent things. covalent substances get softer and softer until they melt. ionic substances melt at one temperature and do not get softer. butter can be a semisolid when it is warm. butter does not hold its shape but it does not flow like a liquid. paint is also a semisolid, since it is highly viscous.