Credit is twice provided in an emergency (6)
I believe the answer is:
crisis
'an emergency' is the definition.
(a crisis is an emergency)
'credit is twice' is the wordplay.
'credit' becomes 'cr' (abbreviation).
'twice' shows that letters should be duplicated.
'is' doubled is 'isis'.
'cr'+'isis'='CRISIS'
'provided in' acts as a link.
(Other definitions for crisis that I've seen before include "Turning point in disease" , "disaster" , "Moment of danger" , "Head" , "Crucial point - decision time" .)