Discovered in Whitechapel: an airy veranda? (5)
I believe the answer is:
lanai
'veranda?' is the definition.
(lanai is a kind of veranda)
'discovered in whitechapel an airy' is the wordplay.
'discovered' indicates the answer is hidden within the clue (remove the letters covering the answer in the clue).
'LANAI' is hidden within 'in whitechapel an airy'.
(Other definitions for lanai that I've seen before include "Place where Hawaiians live" , "Hawaiian veranda" , "Hawaiian living area" .)