Bishop takes steps to get an inflated bag (7)
I believe the answer is:
bladder
'an inflated bag' is the definition.
(I've seen this before)
'bishop takes steps' is the wordplay.
'bishop takes' becomes 'b' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'steps' becomes 'ladder' (ladder is a kind of steps).
'b'+'ladder'='BLADDER'
'to get' acts as a link.
Can you help me to learn more?
(Other definitions for bladder that I've seen before include "may be subject to inflation?" , "Chamber" , "Bag containing liquid or gas" , "Inflated bag" , "Distensible bag" .)