Source of reconstruction in London, say (4)
I believe the answer is:
wren
'source of reconstruction in london say' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'source of reconstruction in london say' is the wordplay.
'source of' suggests taking the first letters (the start - or source - of the word).
'in' means one lot of letters goes inside another.
'london say' becomes 'wen' (wen could historically mean a large city).
The first letter of 'reconstruction' is 'r'.
'r' going inside 'wen' is 'WREN'.
Can you help me to learn more?
(Other definitions for wren that I've seen before include "Small active brown northern hemisphere bird" , "Bird - former British servicewoman" , "Navy girl" , "held up by wings at small scale?" , "Small bird - great architect" .)