Instinctive activity to do with washing clothes (9)
I believe the answer is:
breathing
'instinctive activity' is the definition.
'breathing' can be an answer for 'activity' (breathing is a kind of activity). I'm unsure of the 'instinctive' bit.
'to do with washing clothes' is the wordplay.
'to do with' becomes 're' (regarding).
'washing' becomes 'bathing' (bathing is a kind of washing).
'clothes' indicates putting letters inside.
're' going into 'bathing' is 'BREATHING'.
Can you help me to learn more?
(Other definitions for breathing that I've seen before include "Respiration" , "Respiring" , "(Of wine) exposed to fresh air" , "It's inspiring" , "showing a sign of life" .)