Usual girl getting left behind (6)
I believe the answer is:
normal
'usual' is the definition.
(I've seen this before)
'girl getting left behind' is the wordplay.
I cannot quite see how this works, but
'girl' could be 'norma' and 'norma' is present in the answer.
'left' could be 'l' (common abbreviation) and 'l' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for normal that I've seen before include "Conforming to what is usual" , "Accustomed" , "Average or ordinary" , "Ordinary, usual" , "Usual - sane" .)