Act for traveller with grudge (9)
I believe the answer is:
represent
'act for' is the definition.
(I've seen this before)
'traveller with grudge' is the wordplay.
'traveller' becomes 'rep' (travel company worker).
'with' says to put letters next to each other.
'grudge' becomes 'resent' (I've seen this in other clues).
'rep'+'resent'='REPRESENT'
(Other definitions for represent that I've seen before include "Act for" , "Explain" , "Stand for or symbolise" , "Play the part" , "declare" .)