One advising blokes to rest initially (6)
I believe the answer is:
mentor
'one advising' is the definition.
(someone who advises someone else)
'blokes to rest initially' is the wordplay.
'blokes' becomes 'men' (bloke can informally mean a man).
'initially' suggests taking the first letters.
The initial letter of 'rest' is 'r'.
'men'+'to'+'r'='MENTOR'
(Other definitions for mentor that I've seen before include "A wise and experienced teacher" , "Wise and trusted adviser" , "Wise and experienced counsellor" , "Guru" , "Counsellor/guide" .)