Copy a girl, sadly (4)
I believe the answer is:
alas
'sadly' is the definition.
('alas' is used to express regret)
'copy a girl' is the wordplay.
I cannot quite see how this works, but
'a' is within the answer.
The remaining letters 'las' 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 alas that I've seen before include "What a shame!" , "Regretfully!" , "Expression of grief/pity" , "Interjection of sorrow" , "Exclamation of misfortune" .)