Flexible credit reduced after mounting auction (7)
I believe the answer is:
elastic
'flexible' is the definition.
(I know that flexible can be written as elastic)
'credit reduced after mounting auction' is the wordplay.
'credit reduced' becomes 'tic' (I can't justify this - if you can you should give a lot more credence to this answer).
'after' is a charade indicator (letters next to each other).
'mounting' is a reversal indicator (in a down clue, letters mount or go up).
'auction' becomes 'sale' (type of sale).
'sale' back-to-front is 'elas'.
'tic' put after 'elas' is 'ELASTIC'.
Can you help me to learn more?
(Other definitions for elastic that I've seen before include "Fluid" , "capable of adapting to change?" , "It's lace (anag.)" , "Flexible, adaptable" , "Ductile" .)