Uncle Andrew has a wash (5)
I believe the answer is:
clean
'a wash' is the definition.
(I've seen this before)
'uncle andrew has' is the wordplay.
'has' indicates the answer is hidden within the clue.
'CLEAN' can be found hidden inside 'uncle andrew'.
(Other definitions for clean that I've seen before include "Completely (colloq.), free of dirt" , "far from blue" , "Without stain" , "Quite" , "Not soiled, free from dirt" .)