A smidgen of sand is a very small amount, usually referring to the size of a GRAIN of sand. A GRAIN of sand is a tiny particle of rock or mineral that is found in the environment. It is often used as an analogy for something that is very small and insignificant. The term 'smidgen of sand' can be used to describe a very small amount of something, such as a tiny bit of knowledge or a tiny amount of money. The crossword solution for the term 'smidgen of sand' is 'GRAIN, ' which is a five-letter word that refers to a single particle of sand.