Blustering man not yet content (5)
I believe the answer is:
gusty
'blustering' is the definition.
(synonyms)
'man not yet content' is the wordplay.
'man' becomes 'guy' (guy is a kind of man).
'not yet' becomes 'st' (I can't explain this - if you can you should give a lot more credence to this answer).
'content' means one lot of letters goes inside another (some letters act as content for another word).
'guy' placed around 'st' is 'GUSTY'.
Can you help me to learn more?
(Other definitions for gusty that I've seen before include "Of wind, blowing in bursts" , "Windy" , "Blowing intermittently" .)