Sorry a girl’s lost, that is (3)
I believe the answer is:
sad
'sorry a girl's lost that is' is the definition.
'sad' can be an answer for 'sorry' (I've seen this before). I'm unsure of the rest of the definition.
'sorry a girl's lost that is' is the wordplay.
'sorry' becomes 'sa' (I can't explain this - if you can you should give a lot more credence to this answer).
'a girl's' becomes 'dis'.
'lost' is a deletion indicator.
'that is' becomes 'is'.
'dis' with 'is' removed is 'd'.
'sa'+'d'='SAD'
Can you help me to learn more?
(Other definitions for sad that I've seen before include "grey" , "Despondent" , "Dejected" , "Deplorable" , "Doleful" .)