Corporation taking to graduate in school (7)
I believe the answer is:
stomach
'corporation' is the definition.
(thesaurus)
'to graduate in school' is the wordplay.
'graduate' becomes 'ma' (abbreviation for Master of Arts).
'in' indicates putting letters inside.
'school' becomes 'sch'.
'to'+'ma'='toma'
'toma' put into 'sch' is 'STOMACH'.
'taking' acts as a link.
(Other definitions for stomach that I've seen before include "Saclike organ" , "Tummy" , "Put up with" , "Digestive organ" , "Could Mac host this organ?" .)