Confused lips utter imperfectly (4)
I believe the answer is:
lisp
'utter imperfectly' is the definition.
'confused lips' is the wordplay.
'confused' is an anagram indicator.
'lips' with letters rearranged gives 'LISP'.
(Other definitions for lisp that I've seen before include "Speak with defective sibilants" , "speak imperfectly" , "Talk like thith" , "Non-standard pronunciation" , "Thpeak like thith" .)