concertina
    n 1: coiled barbed wire used as an obstacle
    2: free-reed instrument played like an accordion by pushing its
       ends together to force air through the reeds
    v 1: collapse like a concertina

Concertina \Con`cer*ti"na\, n. [From It. concerto a concert.]
   A small musical instrument on the principle of the accordion.
   It is a small elastic box, or bellows, having free reeds on
   the inside, and keys and handles on the outside of each of
   the two hexagonal heads.
   [1913 Webster]