Rant - read it, bewildered (6)
I believe the answer is:
tirade
'rant' is the definition.
(thesaurus)
'read it bewildered' is the wordplay.
'bewildered' indicates anagramming the letters.
'read'+'it'='readit'
'readit' is an anagram of 'TIRADE'.
(Other definitions for tirade that I've seen before include "A long, vehement harangue" , "Verbal onslaught" , "Long angry harangue" , "Torrent of abuse" , "strong words" .)