This is the 1998th most frequent Portuguese word.
areia
Sand.
Here, 'areia' refers to the sand found at the beach, used for building sandcastles.
Eu construí um castelo de areia na praia.
I built a sandcastle on the beach.
In this sentence, 'areia' is used in the compound noun 'areia movediça' (quicksand), highlighting its context as a type of dangerous sand.
Cuidado para não pisar na areia movediça.
Be careful not to step into the quicksand.
This usage of 'areia' pertains to the sand characteristic of a desert landscape.