Heard a girl's sad cry (4)
I believe the answer is:
alas
'sad cry' is the definition.
(I've seen this in another clue)
'heard a girl's' 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 understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for alas that I've seen before include "Regretfully!" , "Expression of grief or misfortune" , "Exclamation of grief" , "Sadly, unfortunately" , "Lackaday" .)