Unlimited oil and unction flowing (13)
I believe the answer is:
unconditional
'unlimited' is the definition.
(thesaurus)
'oil and unction flowing' is the wordplay.
'flowing' indicates anagramming the letters.
'oil'+'and'+'unction'='oilandunction'
'oilandunction' anagrammed gives 'UNCONDITIONAL'.
(Other definitions for unconditional that I've seen before include "Under all circumstances" , "Not qualified" , "Without any ifs or buts" , "Without reservation" , "Absolute, unlimited" .)