What's left of cash after my leaving United (3)
I believe the answer is:
one
'united' is the definition.
(as in a phrase like 'we are one')
'what's left of cash after my' is the wordplay.
I cannot quite see how this works, but
'of' could be 'o' and 'o' is located in the answer.
The remaining letters 'ne' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'leaving' acts as a link.
Can you help me to learn more?
(Other definitions for one that I've seen before include "Unity" , "SECOND PART OF 16" , "This is singular" , "Lowest cardinal number" , "both halves" .)