Not in school at first, dig new head's candour (13)
I believe the answer is:
outspokenness
'candour' is the definition.
(I've seen this before)
'not in school at first dig new head's' is the wordplay.
I cannot quite see how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is found within the answer.
'school' could be 's' and 's' is present in the answer.
'dig' could be 'poke' (synonyms) and 'poke' is found within the answer.
'new' could be 'n' (common abbreviation eg NT for New Testament) and 'n' is located in the answer.
'head' could be 'ness' (ness is a headland) and 'ness' is found within the answer.
The remaining letters 'ut' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for outspokenness that I've seen before include "Candour" , "Lack of verbal restraint" .)