I do break into it, like a fool (5)
I believe the answer is:
idiot
'a fool' is the definition.
(thesaurus)
'i do break into it' is the wordplay.
'break' indicates an anagram.
'into' is an insertion indicator.
'i'+'do'='ido'
'ido' with letters rearranged gives 'dio'.
'dio' placed inside 'it' is 'IDIOT'.
'like' is the link.
(Other definitions for idiot that I've seen before include "Imbecile" , "'The -----'. novel by Dostoyevsky (1868)" , "Dunce" , "Dolt" , "Dope" .)