Study hollow that’s saucer-shaped (7)
I believe the answer is:
concave
'saucer-shaped' is the definition.
(thesaurus)
'study hollow' is the wordplay.
'study' becomes 'con' (I've seen this before).
'hollow' becomes 'cave' (caving is a kind of hollowing).
'con'+'cave'='CONCAVE'
'that's' acts as a link.
(Other definitions for concave that I've seen before include "Curving inward" , "Curving inwards" , "Bowing" , "Cupped" , "Arch" .)