Hard-shelled fruits are fruits that have a hard outer shell or skin. GOURD is a type of hard-shelled fruit with five letters and is a member of the squash family. COCONUT is another type of hard-shelled fruit with seven letters and is a drupe, meaning it has a hard outer layer surrounding a single seed. NUT is also a type of hard-shelled fruit with three letters and is a dry fruit with a hard outer shell and edible kernel inside.