Doughnut shape (5)
I believe the answer is:
torus
'doughnut shape' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for torus that I've seen before include "Ring shaped like doughnut with hole" , "Doughnut-shaped solid" , "Shape of doughnut" , "Ring-shaped object" , "Ring-doughnut shape" .)