Suggestion about Queen's houses (7)
I believe the answer is:
terrace
'houses' is the definition.
(I've seen this before)
'suggestion about queen's' is the wordplay.
'suggestion' becomes 'trace' (synonyms).
'about' indicates putting letters inside.
'queen' becomes 'ER' (abbreviation for Elizabeth Regina).
'trace' enclosing 'er' is 'TERRACE'.
(Other definitions for terrace that I've seen before include "Continuous row of houses" , "Stadium's standing area" , "Row of houses in one block" , "Hillside level" , "Bank - houses in a row" .)