Notice work not starting to be of use (7)
I believe the answer is:
observe
'notice' is the definition.
(I know that notice can be written as observe)
'work not starting to be of use' is the wordplay.
'work' becomes 'obs' (I can't explain this - if you can you should give a lot more credence to this answer).
'not starting' means to remove the first letter.
'to be of use' becomes 'serve' (I've seen this in another clue).
'serve' with its first letter taken away is 'erve'.
'obs'+'erve'='OBSERVE'
Can you help me to learn more?
(Other definitions for observe that I've seen before include "Discern" , "Espy" , "Notice, watch" , "Keep; notice" , "Abide by -- watch" .)