Help! Turf her out! (7)
I believe the answer is:
further
'help' is the definition.
(thesaurus)
'turf her out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'turf'+'her'='turfher'
'turfher' anagrammed gives 'FURTHER'.
(Other definitions for further that I've seen before include "To, or at, a greater extent, degree, or a more advanced stage" , "To somewhere more advanced" , "In addition, also" , "Moreover" , "More distant" .)