If something is sandyish, it is somewhat like sand or has some sand in it.
Sandyish can make people think of beaches, deserts, or sandcastles.
Examples:
The beach is sandyish.
The cake has a sandyish texture.
Her shoes are sandyish from the beach.
The cat's fur feels sandyish.
The desert is very sandyish, with sand everywhere.
The cookies taste sandyish because they have some sand in them.