Always in drawing room, going away different (7)
I believe the answer is:
several
'different' is the definition.
(thesaurus)
'always in drawing room' is the wordplay.
'always' becomes 'ever' (synonyms).
'in' means one lot of letters goes inside another.
'drawing room' becomes 'sal' (I can't justify this - if you can you should give a lot more credence to this answer).
'ever' inserted into 'sal' is 'SEVERAL'.
'going away' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for several that I've seen before include "Reveals (anag.)" , "Some participants" , "More than one or two" , "Various, sundry" , "Indefinite number more than two or three, but not many" .)