Six-footer girl rebuffed one feels (7)
I believe the answer is:
antenna
'one feels' is the definition.
(an antenna feels things)
'six-footer girl rebuffed' is the wordplay.
'six footer' becomes 'ant' (an ant has six feet).
'girl' becomes 'Anne' (girl's name).
'rebuffed' says the letters should be written in reverse.
'anne' reversed gives 'enna'.
'ant'+'enna'='ANTENNA'
(Other definitions for antenna that I've seen before include "one feels" , "Aerial - insect feeler" , "Feeling part" , "sensitive feeler" , "could send out a message" .)