One presenting an unwelcome task left incomplete by crew (9)
I believe the answer is:
anchorman
'one presenting' is the definition.
(type of TV presenter)
'an unwelcome task left incomplete by crew' is the wordplay.
'unwelcome task' becomes 'chore' (I've seen this before).
'left incomplete' means to remove the last letter.
'by' is a charade indicator (letters next to each other).
'crew' becomes 'man' (I've seen this before).
'chore' with its final letter taken off is 'chor'.
'an'+'chor'+'man'='ANCHORMAN'
(Other definitions for anchorman that I've seen before include "who winds up relay?" , "Maybe last person to run" , "Crucial participant" , "Last runner in a relay race - person presenting a TV show" , "Last person in relay race - TV presenter" .)