What initially remains in the laundry? (4)
I believe the answer is:
wash
'the laundry?' is the definition.
('wash' can be a synonym of 'laundry')
'what initially remains' is the wordplay.
'initially' says to take the initial letters.
'remains' becomes 'ash' (I've seen this before).
The initial letter of 'what' is 'w'.
'w'+'ash'='WASH'
'in' acts as a link.
(Other definitions for wash that I've seen before include "Flow over" , "Lave" , "The ----, inlet of the North Sea" , "Clean with soap" , "Rough water left by a moving boat" .)