Press crumpled rug with energy (4)
I believe the answer is:
urge
'press' is the definition.
('urge' can be a synonym of 'press')
'crumpled rug with energy' is the wordplay.
'crumpled' is an anagram indicator.
'with' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mc2**).
'rug' is an anagram of 'urg'.
'urg'+'e'='URGE'
(Other definitions for urge that I've seen before include "Plead" , "Advise earnestly, encourage to go on" , "Propel, drive onward" , "Persuade - proclivity" , "Strong, restless desire" .)