North Sea estuary used to be close to beach
I believe the answer is:
wash
'north sea estuary' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
'used to be close to beach' is the wordplay.
'used to be' becomes 'was' (eg 'he was...' means 'he used to be...').
'close to' suggests the final letters (the close/ending of).
The last letter of 'beach' is 'h'.
'was'+'h'='WASH'
Can you help me to learn more?
(Other definitions for wash that I've seen before include "Clean with water" , "Clean with soap" , "Clean; dilute coat" , "Brush with ink; launder" , "put on thin coat" .)