Rigid cord used on repaired net (9)
I believe the answer is:
stringent
'rigid' is the definition.
(thesaurus)
'cord used on repaired net' is the wordplay.
'cord' becomes 'string' (string is a kind of cord).
'used on' means one lot of letters go next to another.
'repaired' indicates anagramming the letters.
'net' is an anagram of 'ent'.
'string'+'ent'='STRINGENT'
(Other definitions for stringent that I've seen before include "Strict, precise, exacting" , "Demanding, inflexible" , "(Rule) allowing no discretion" , "Of rule, say strict and precise" , "Strict, rigorous" .)