Insightful story I used in company (American) (9)
I believe the answer is:
sagacious
'insightful' is the definition.
(thesaurus)
'story i used in company american' is the wordplay.
'story' becomes 'saga' (saga is a kind of story**).
'used in' means one lot of letters goes inside another.
'company' becomes 'co' (abbreviation).
'american' becomes 'us'.
'i' going within 'co' is 'cio'.
'saga'+'cio'+'us'='SAGACIOUS'
(Other definitions for sagacious that I've seen before include "Wise" , "Astute" .)