Original chap demanding attention (6)
I believe the answer is:
urgent
'demanding attention' is the definition.
'original chap' is the wordplay.
'original' becomes 'ur'.
'chap' becomes 'gent' (I've seen this in other clues**).
'ur'+'gent'='URGENT'
(Other definitions for urgent that I've seen before include "Pressing, imperative" , "Calling for immediate attention" , "Pressing, immediate" , "Requiring immediate attention" , "High priority" .)