Clue idiot's rewritten causing anxiety (10)
I believe the answer is:
solicitude
'anxiety' is the definition.
(thesaurus)
'clue idiot's rewritten' is the wordplay.
'rewritten' indicates anagramming the letters.
'clue'+'idiots'='clueidiots'
'clueidiots' anagrammed gives 'SOLICITUDE'.
'causing' is the link.
(Other definitions for solicitude that I've seen before include "Care, concern" , "Feeling of excessive concern" .)