VIP lifted prohibition of humming (5)
I believe the answer is:
nabob
'vip' is the definition.
(I've seen this before)
'lifted prohibition of humming' is the wordplay.
'lifted' is a reversal indicator (going up in down clue).
'prohibition' becomes 'ban' (ban is a kind of prohibition).
'of humming' becomes 'ob' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ban' in reverse letter order is 'nab'.
'nab'+'ob'='NABOB'
Can you help me to learn more?
(Other definitions for nabob that I've seen before include "Mogul governor; very rich or important person" , "Person of conspicuous wealth or high status" , "he may be loaded" , "Wealthy and powerful person" , "Devotional painting" .)