Ten-sided shape (7)
I believe the answer is:
decagon
'ten-sided shape' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for decagon that I've seen before include "Go, dance on geometric figure with ten sides" , "A polygon -- eg can-do (anag)" , "Figure with 10 sides" , "Ten-sided plane figure" , "Plane shape" .)