Collapse of show in America (10)
I believe the answer is:
concertina
'collapse' is the definition.
(concertinaing is a kind of collapsing)
'show in america' is the wordplay.
'show' becomes 'concert' (concert is a kind of show**).
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'concert'+'in'+'a'='CONCERTINA'
'of' acts as a link.
(Other definitions for concertina that I've seen before include "Crush" , "Musical instrument with bellows" , "Squeeze-box" , "fold" , "Collapse" .)