One advising me to start to relax around noon (6)
I believe the answer is:
mentor
'one advising' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'me to start to relax around noon' is the wordplay.
'start to' suggests taking the first letters.
'around' is an insertion indicator.
'noon' becomes 'n'.
The initial letter of 'relax' is 'r'.
'me'+'to'+'r'='metor'
'metor' enclosing 'n' is 'MENTOR'.
Can you help me to learn more?
(Other definitions for mentor that I've seen before include "One who steers" , "A trusted adviser or teacher" , "Wise and experienced counsellor" , "Somebody advising" , "No term for instructor" .)