Region's last Neanderthal? He didn't quite make it (6,3)
I believe the answer is:
nearly man
'he didn't quite make it' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'region's last neanderthal?' is the wordplay.
'region's last' becomes 'nearly' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'neanderthal?' becomes 'man' (neanderthal is a kind of man).
'nearly'+'man'='NEARLY MAN'
Can you help me to learn more?
(Other definitions for nearly man that I've seen before include "one who didn't quite make it" , "not the expected success" , "one failing to fulfil his potential" , "underachiever?" , "Teenage boy is" .)