Diamond.
A shape that has a name consisting of seven letters could be a hexagon. A hexagon is a six-sided polygon.
ellipse
Hexagon
hexagon?
DODECAHEDRON
what is the opposite of smoother in seven letters
Both advisor and counsel have seven letters.
This color is chestnut or auburn but not seven letters.
There is no such shape.
A 2D shape that has four sides and is thirteen letters long is a quadrilateral.
Yes, "tornado" is a natural disaster with seven letters.
Demeter and Artemis are Greek goddesses with seven letters in their names.