Wide-ranging former contract split by four (9)
I believe the answer is:
extensive
'wide-ranging' is the definition.
(synonyms)
'former contract split by four' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'contract' becomes 'tense' (I've seen this before).
'split by' indicates putting letters inside.
'four' becomes 'IV' (roman numeral).
'tense' placed around 'iv' is 'tensive'.
'ex'+'tensive'='EXTENSIVE'
(Other definitions for extensive that I've seen before include "terribly large" , "Comprehensive" , "Covering a wide area" , "Broad in scope" , "Exist even being wide-ranging" .)