Fancy estate houses I'll flipping moon? (9)
I believe the answer is:
satellite
'moon?' is the definition.
(thesaurus)
'fancy estate houses i'll flipping' is the wordplay.
'fancy' indicates anagramming the letters.
'houses' indicates putting letters inside.
'flipping' says the letters should be written in reverse.
'ill' back-to-front is 'lli'.
'estate' with letters rearranged gives 'satete'.
'satete' enclosing 'lli' is 'SATELLITE'.
(Other definitions for satellite that I've seen before include "Body moving around a planet" , "dependent community" , "space station, perhaps" , "Space traveller" , "important person's attendant" .)