Backache caused by taking piano out of plant (7)
I believe the answer is:
lumbago
'backache' is the definition.
(I know that lumbago is a type of backache)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lumbago that I've seen before include "Painful condition" , "Back problem" , "Gaul mob (anag.)" , "Back complaint" , "Pain -- a bum log (anag)" .)