In dining room English crazy about French ladies (8)
I believe the answer is:
mesdames
'french ladies' is the definition.
(I've seen this before)
'in dining room english crazy about' is the wordplay.
'in' means one lot of letters goes inside another.
'dining room' becomes 'mess' (mess is a kind of dining room).
'english' becomes 'E' (abbreviation as in OED).
'crazy' becomes 'mad' (synonyms).
'about' is a reversal indicator.
'e'+'mad'='emad'
'emad' backwards is 'dame'.
'mess' going around 'dame' is 'MESDAMES'.
(Other definitions for mesdames that I've seen before include "Messieurs et ... - French ladies" , "Ladies and gentlemen; ........ et monsieurs" .)