Upset Catholic is repeatedly creating emergency (6)
I believe the answer is:
crisis
'emergency' is the definition.
(thesaurus)
'upset catholic is repeatedly' is the wordplay.
'upset' shows that the letters should be reversed in order.
'catholic' becomes 'rc' (I've seen this in other clues).
'repeatedly' indicates the doubling of some letters.
'rc' back-to-front is 'cr'.
'is' duplicated is 'isis'.
'cr'+'isis'='CRISIS'
'creating' acts as a link.
(Other definitions for crisis that I've seen before include "crucial period" , "Turning point in disease" , "a difficult situation" , "Emergency (in midlife?)" , "Time of intense difficulty or danger" .)