Smiles awkwardly at a girl (7)
I believe the answer is:
melissa
'girl' is the definition.
'smiles awkwardly at a' is the wordplay.
'awkwardly' indicates anagramming the letters.
'at' means one lot of letters go next to another.
'smiles' anagrammed gives 'meliss'.
'meliss'+'a'='MELISSA'
(Other definitions for melissa that I've seen before include "Female" , "Girl's name meaning "bee"" , "woman" .)