Stallone bags modern gallery in August (7)
I believe the answer is:
stately
'august' is the definition.
(august can mean stately or noble)
'stallone bags modern gallery' is the wordplay.
'stallone' becomes 'sly' (nickname for Sylvester Stallone).
'bags' means one lot of letters goes inside another (bag can mean secures or steals).
'modern gallery' becomes 'tate' (Tate Modern, Tate Britain etc. I am not sure about the 'modern' bit.).
'sly' going around 'tate' is 'STATELY'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for stately that I've seen before include "Imperial" , "Imposing, grand" , "Courtly; imposing" , "Impressive in appearance; majestic" , "Impressive in manner" .)