Fool roaming all over the place with American (9)
I believe the answer is:
ignoramus
'fool' is the definition.
(thesaurus)
'roaming all over the place with american' is the wordplay.
'all over the place' is an anagram indicator.
'with' says to put letters next to each other.
'american' becomes 'us'.
'roaming' with letters rearranged gives 'ignoram'.
'ignoram'+'us'='IGNORAMUS'
(Other definitions for ignoramus that I've seen before include "Dimwit" , "Simpleton" , "Imbecile" , "Stupid person" , "Fool" .)