Hard work, getting a new motto (6)
I believe the answer is:
slogan
'motto' is the definition.
(I know that motto can be written as slogan)
'hard work getting a new' is the wordplay.
'hard work' becomes 'slog' (a slog is a long or difficult task).
'getting' is a charade indicator (letters next to each other).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'slog'+'a'+'n'='SLOGAN'
(Other definitions for slogan that I've seen before include "Battle cry - advertising phrase" , "Word or phrase adopted as motto" , "Shibboleth" , "Identifying catchword" , "Advertising catchphrase" .)