Short communication about a junior cleaner (11)
I believe the answer is:
launderette
'cleaner' is the definition.
(launderettes clean laundry)
'short communication about a junior' is the wordplay.
I cannot quite understand how this works, but
'about' could be 're' (regarding) and 're' is found within the answer.
'a' is found in the answer.
This explanation may well be incorrect...
(Other definitions for launderette that I've seen before include "Scene of washing machines" , "high street establishment" , "self-service establishment" , "Washing establishment" , "Place for washing and drying clothes" .)