Number one gentleman, full of energy, creating more commotion (7)
I believe the answer is:
noisier
'creating more commotion' is the definition.
'number one gentleman full of energy' is the wordplay.
'number' becomes 'no' (abbreviation for 'number').
'one' becomes 'i' (Roman numeral).
'gentleman' becomes 'sir' (I've seen this before).
'full of' is an insertion indicator.
'energy' becomes 'e' (physics symbol as in E=mc2).
'sir' placed around 'e' is 'sier'.
'no'+'i'+'sier'='NOISIER'
(Other definitions for noisier that I've seen before include "more deafening!" , "More rowdy" , "Less quiet" , "More loud" , "Perhaps more disturbing" .)