International gallery without frame for Modigliani copy (7)
I believe the answer is:
imitate
'modigliani copy' is the definition.
'imitate' can be an answer for 'copy' (I've seen this in another clue). I am not sure about the 'modigliani' bit.
'international gallery without frame' is the wordplay.
'international' becomes 'i' (abbreviation eg in IMF).
'gallery' becomes 'tate' (Tate Modern, Tate Britain etc).
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'frame' becomes 'mi' (I can't explain this - if you can you should give a lot more credence to this answer).
'i'+'tate'='itate'
'itate' enclosing 'mi' is 'IMITATE'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for imitate that I've seen before include "Fake" , "Copy someone" , "'Ape, copy (7)'" , "I tame it (anag)" , "Take as a model" .)