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?
what is the opposite of smoother in seven letters
DODECAHEDRON
Both advisor and counsel have seven letters.
This color is chestnut or auburn but not seven letters.
There are several:TsunamiTornadoVolcanoLocusts
Demeter and Artemis are Greek goddesses with seven letters in their names.
A word that has seven letters is unknown, in French: 'inconnu'.
Seven Years of Letters was created on 2009-10-19.