Souped up international Catholic organisation (4,3)
I believe the answer is:
opus dei
'catholic organisation' is the definition.
(I've seen this before)
'souped up international' is the wordplay.
'up' is an anagram indicator (letters get chucked up).
'international' becomes 'i' (abbreviation eg in IMF).
'souped' is an anagram of 'opusde'.
'opusde'+'i'='OPUS DEI'
(Other definitions for opus dei that I've seen before include "A religious organisation" , "prayers" , "(Christian) liturgical duty to God" , "Oedipus (anag) - divine liturgy - international Roman Catholic organisation" , "RC organisation which maintains various universities" .)