Flattened at the poles (6)
I believe the answer is:
oblate
'flattened at the poles' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for oblate that I've seen before include "Of spheroid, flattened at the poles" , "a religious person" , "Top-flattened (sphere)" , "One bound to religious life" , "monastic dedicatee" .)