Good when device reduced stomach (7)
I believe the answer is:
gastric
'stomach' is the definition.
(I've seen this before)
'good when device reduced' is the wordplay.
I cannot really see how this works, but
'good' could be 'g' (abbreviation) and 'g' is found within the answer.
'when' could be 'as' (eg 'when I walked' means 'as I walked') and 'as' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for gastric that I've seen before include "of the corporation?" , "Intestinal" , "Stomachic" , "Relating to or involving the stomach" , "touching stomach" .)