[ sand-kas-uh l, -kah-suh l ]
/ ˈsændˌkæs əl, -ˌkɑ səl /
a small castlelike structure made of wet sand, as by children at a beach.
a plan or idea with little substance.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for sandcastle
No one likes it when their sandcastle is knocked over, but his reaction is a bit, err, extreme.
Midweek, Mercury retreads over the Sun and Venus in Leo, so best-laid plans will be as solid as a sandcastle in the incoming tide.