Flooded a laundry (5)
I believe the answer is:
awash
'flooded' is the definition.
(synonyms)
'a laundry' is the wordplay.
'laundry' becomes 'wash' (synonyms).
'a'+'wash'='AWASH'
(Other definitions for awash that I've seen before include "Flood" , "Letting the 21 in" , "Flooded; about to sink" , "Letting in the sea" , "With the top just covered with water" .)