Not all fear a Cheltenham girl (6)
I believe the answer is:
rachel
'girl' is the definition.
(girl's name)
'not all fear a cheltenham' is the wordplay.
'not all' indicates a hidden word (only some of the letters).
'RACHEL' can be found hidden inside 'fear a cheltenham'.
(Other definitions for rachel that I've seen before include "Second wife of Jacob" , "Import illicitly" , "Heal RC of the girl" , "Female" , "Woman" .)