Attempting to be annoying (6)
I believe the answer is:
trying
I believe this clue is a double definition.
'attempting' is the first definition.
('try' can be a synonym of 'attempt')
'be annoying' is the second definition.
(I've seen this before)
'to' acts as a link.
(Other definitions for trying that I've seen before include "Bothersome" , "Annoying; sampling" , "Testing" , "Doing one's best - annoying!" , "Hard to endure" .)