Acquire tainted ingredients and hold them back (6)
I believe the answer is:
retain
'hold them back' is the definition.
I can't tell whether this definition defines the answer.
'acquire tainted ingredients' is the wordplay.
'ingredients' indicates the answer is hidden within the clue (certain parts or ingredients from the clue).
'RETAIN' is hidden within 'acquire tainted'.
'and' acts as a link.
Can you help me to learn more?
(Other definitions for retain that I've seen before include "Save" , "'Hold, keep back (6)'" , "Keep in place" , "Keep, hold on to something" , "Continue to hold on to" .)