concertina

US /ˌkɑːn.sɚˈtiː.nə/
UK /ˌkɑːn.sɚˈtiː.nə/
"concertina" picture
1.

a small musical instrument, similar to an accordion, with bellows and buttons or keys for playing notes

:
•
He played a lively tune on his concertina.
•
The folk band featured a fiddle, a guitar, and a concertina.
1.

fold or compress into a series of folds, like the bellows of a concertina

:
•
The metal barrier concertinaed on impact.
•
The car's front end concertinaed after hitting the wall.
:
foldcompresscrumplecollapsepleat