Madam Weisberg's top immoral houses (4)

I believe the answer is:

bawd

'madam' is the definition.
(I've seen this in another clue)

'weisberg's top immoral houses' is the wordplay.
'top' says to take the initial letters (in a down clue, the first letter is top).
'immoral' becomes 'bad' (synonyms).
'houses' indicates putting letters inside.
The initial letter of 'weisberg' is 'w'.
'w' placed into 'bad' is 'BAWD'.

(Another definition for bawd that I've seen is " Madam".)

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app