Helper shaking doormats again (4,9)
I believe the answer is:
good samaritan
'helper' is the definition.
(good Samaritan is a kind of helper)
'shaking doormats again' is the wordplay.
'shaking' indicates an anagram.
'doormats'+'again'='doormatsagain'
'doormatsagain' anagrammed gives 'GOOD SAMARITAN'.
(Other definitions for good samaritan that I've seen before include "One helping the needy" , "Charitable person (with ref. to Luke 10:33)" , "One giving disinterested help, maybe to a stranger" , "Neighbourly type" , "Philanthropist" .)