American with endearing accent (5)
I believe the answer is:
acute
'accent' is the definition.
(acute is a kind of accent)
'american with endearing' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'with' says to put letters next to each other.
'endearing' becomes 'cute' (I've seen this before).
'a'+'cute'='ACUTE'
(Other definitions for acute that I've seen before include "Canny" , "Short and severe" , "(Of an angle) less than 90deg" , "Penetrating; accent" , "Quick-witted" .)