The highest of the high, in particular (5,3)
I believe the answer is:
above all
'in particular' is the definition.
Both the definition and answer are adverbs. Perhaps there's a link between them I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for above all that I've seen before include "Supremely" , "Especially" , "Like the managing director" , "What 18 [EVEREST] is" , "Hamlet : 'This . . . . . . . ., to thine own self be true'" .)