Get back to illustrate in the shower (6)
I believe the answer is:
regain
'get back' is the definition.
(I've seen this before)
'illustrate in the shower' is the wordplay.
'illustrate' becomes 'eg' (I can't explain this - if you can you should believe this answer much more).
'in the' means one lot of letters goes inside another.
'shower' becomes 'rain' (rainfall).
'eg' inserted within 'rain' is 'REGAIN'.
'to' is the link.
Can you help me to learn more?
(Other definitions for regain that I've seen before include "Recover, retrieve" , "Win back" , "Take back (the Ashes, for example)" , "Get back, recover the use of" , "Recover - in gear (anag)" .)