Needing immediate attention (6)
I believe the answer is:
urgent
'needing immediate attention' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for urgent that I've seen before include "To be done asap" , "Earnest, insistent" , "Requiring early action" , "In need of immediate action" , "Pressing, compelling" .)