Horribly cheat coach (5)
I believe the answer is:
teach
'coach' is the definition.
(thesaurus)
'horribly cheat' is the wordplay.
'horribly' indicates an anagram.
'cheat' is an anagram of 'TEACH'.
(Other definitions for teach that I've seen before include "Work with pupils" , "show" , "Educate 4 across" , "Act as director" , "Give instruction to" .)