Charlie possibly having been dumped by girl of no obvious distinction? (9)
I believe the answer is:
classless
'distinction?' is the definition.
(I have seen 'Lacking distinction' mean 'classless' so perhaps 'distinction' could also mean 'classless')
'charlie possibly having been dumped by girl of no obvious' is the wordplay.
I cannot quite see how this works, but
'charlie' could be 'ass' (both can mean a foolish person) and 'ass' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for classless that I've seen before include "Society of socialist ideal" , "Lacking distinction" , "lacking social order" , "like an unemployed teacher" , "having no social distinctions" .)