Miss head after class's first friendship (9)
I believe the answer is:
closeness
'friendship' is the definition.
(thesaurus)
'miss head after class's first' is the wordplay.
I cannot quite see how this works, but
'miss' could be 'lose' (I've seen this in other clues) and 'lose' is found within the answer.
'head' could be 'ness' (type of geographical point) and 'ness' is found in the answer.
'class's first' could be 'c' (1st letter of 'class') and 'c' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for closeness that I've seen before include "State of being very near" , "Proximity" , "sense of unity" .)