- a small castlelike structure made of wet sand, as by children at a beach.
- a plan or idea with little substance.
Origin of sandcastle
Examples from the Web for sand-castle
Historical Examples of sand-castle
But it's my idea that Miss Allonby has too much insight to build herself such a sand-castle.The Tree of Knowledge
Mrs. Baillie Reynolds
The sand-castle on which Pollyooly and Kathleen had worked so hard stood directly in the line of it.
After a while the children tired of rounders and betook themselves to building a sand-castle.