Irish city gettin' twice as big, we hear (6)
I believe the answer is:
dublin
'irish city' is the definition.
(I've seen this before)
'gettin' twice as big we hear' is the wordplay.
I cannot really understand how this works, but
'as' could be 'in' (I've seen this in other clues) and 'in' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dublin that I've seen before include "Capital of Eire" , "Ulysses city (Joyce)" , "Capital of 8" , "Irish capital city" , "City on the Liffey" .)