Nameless bird, ultimately with scant illumination (9)
I believe the answer is:
starlight
'illumination' is the definition.
(I have seen 'faint illumination' mean 'starlight' so perhaps 'illumination' could also mean 'starlight')
'nameless bird ultimately with scant' is the wordplay.
I cannot really understand how this works, but
'scant' could be 'light' (similar in meaning) and 'light' is found within the answer.
The remaining letters 'star' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for starlight that I've seen before include "faint illumination" , "The illumination of a moonless night" , "faint glimmer" , "Express musically this" , "Twinkling overhead" .)