Turn out fine, ultimately about to go into black (5)
I believe the answer is:
'turn out' is the definition.
('eject' can be a synonym of 'turn out')
'fine ultimately about to go into black' is the wordplay.
'ultimately' indicates one should take the final letters.
'about' becomes 'c' (abbreviation for 'circa'**).
'to go into' means one lot of letters goes inside another.
'black' becomes 'jet' (jet black is a kind of black).
The final letter of 'fine' is 'e'.
'c' put inside 'jet' is 'ject'.
(Other definitions for eject that I've seen before include "Send out forcibly" , "DVD player button" , "Turn out" , "Discharge; evacuate" , "Throw or put out" .)