Ivan's rule terrible in general (9)
I believe the answer is:
universal
'general' is the definition.
(I know that general can be written as universal)
'ivan's rule terrible' is the wordplay.
'terrible' indicates an anagram.
'ivans'+'rule'='ivansrule'
'ivansrule' is an anagram of 'UNIVERSAL'.
'in' is the link.
(Other definitions for universal that I've seen before include "Sort of joint" , "Applicable to all cases" , "affecting everyone" , "Belonging to the whole world" , "Film producer" .)