Describe loan arrangement as significant (12)
I believe the answer is:
considerable
'significant' is the definition.
(similar in meaning)
'describe loan arrangement' is the wordplay.
'arrangement' indicates an anagram.
'describe'+'loan'='describeloan'
'describeloan' with letters rearranged gives 'CONSIDERABLE'.
'as' is the link.
(Other definitions for considerable that I've seen before include "Fairly large or numerous" , "Tidy" , "Great" , "worth entertaining?" , "Notably large" .)