Emergency credit is doubled (6)
I believe the answer is:
crisis
'emergency' is the definition.
(I've seen this before)
'credit is doubled' is the wordplay.
'credit' becomes 'cr'.
'doubled' says to double the letters.
'is' duplicated is 'isis'.
'cr'+'isis'='CRISIS'
(Other definitions for crisis that I've seen before include "Crucial or decisive moment" , "Climacteric" , "Critical point" , "Emergency or turning point" , "a difficult situation" .)