Abbreviated exchange about power walk (5)
I believe the answer is:
tramp
'walk' is the definition.
(tramp can mean to walk around)
'abbreviated exchange about power' is the wordplay.
'abbreviated exchange about' becomes 'tr' (I can't explain this - if you can you should give a lot more credence to this answer).
'power' becomes 'amp'.
'tr'+'amp'='TRAMP'
Can you help me to learn more?
(Other definitions for tramp that I've seen before include "Walk noisily; vagrant" , "Down-and-out" , "Walk heavily and firmly" , "Beggar or vagrant" , "Lady or gentleman of the road or roving ship" .)