Primitive man demanding immediate attention (6)
I believe the answer is:
urgent
'demanding immediate attention' is the definition.
(I've seen this before)
'primitive man' is the wordplay.
'primitive' becomes 'ur'.
'man' becomes 'gent' (I've seen this before**).
'ur'+'gent'='URGENT'
(Other definitions for urgent that I've seen before include "Demanding immediate attention" , "grave?" , "Requiring speedy action" , "In need of immediate action" , "Needing early action" .)