Husband opening food store in megacity (5)
I believe the answer is:
delhi
'megacity' is the definition.
Both the answer and definition are singular nouns.
Maybe there's a link between them I don't understand?
'husband opening food store in' is the wordplay.
'opening' suggests taking the first letters.
'food store' becomes 'deli' (short for delicatessen).
'in' indicates putting letters inside.
The first letter of 'husband' is 'h'.
'h' put within 'deli' is 'DELHI'.
Can you help me to learn more?
(Other definitions for delhi that I've seen before include "Asian city" , "Old city of north central India" , "Capital of India" , "Indian capital city" , "New -, Asian capital" .)